| udder | = | mamma, uber |
| ugly | = | turpis |
| ulcer | = | vomica, ulcus |
| ultimately | = | tandem, extremo |
| un- | = | abs- |
| unaccompanied | = | incomitatus |
| unaccustomed | = | insolita, insolitus |
| unaccustomed, be - (vb) | = | desuesco |
| unacquainted with | = | ignarus |
| unadulterated | = | incontaminatus, putus |
| unaffected | = | simplex |
| unaided | = | sponte |
| unanticipated | = | insperatus |
| unappeasable | = | implacabilis |
| unavenged | = | inultus |
| unavoidability | = | necessitas |
| unavoidable | = | necesse (adj.) |
| unaware | = | insciens |
| unaware, be - | = | nescio |
| unbecoming | = | indignus |
| unbelievable | = | incredibilis |
| unbend | = | retendo |
| unbending | = | inflexibilis, ferreus |
| unbreakable | = | infragilis |
| unbridled | = | infrenis, effrenus |
| unbroken | = | perpetuus |
| unburied | = | inhumatus |
| uncertain | = | hesito (haesito), incertus |
| uncertain, be - | = | pendeo |
| uncertainty | = | ambiguitas, error |
| unchangeable | = | incommutabilis |
| unchanging | = | constans |
| unchecked | = | licens, effrenus, expeditus |
| uncivil | = | inhumanus |
| unclaimed | = | incognitus |
| uncle | = | avunculus, patruus |
| unclean | = | immunda |
| uncoil (vb) | = | explico |
| uncomfortable | = | incommoditas |
| uncommon | = | insolitus, eximius, rarus |
| uncommonly | = | rare, mire |
| uncommonness | = | eximietate |
| unconquer | = | invictus |
| unconquerable | = | inexpugnabilis, invictus |
| unconsumed | = | inconsumptus |
| uncooked | = | crudus, crudus |
| uncorrected | = | incorrectus |
| uncorrupted | = | incorruptus |
| uncouth | = | barbarus |
| uncouthly | = | barbare |
| uncover (vb) | = | aperio |
| uncrowded | = | infrequens |
| uncultivated | = | incultus, rudis, incultus |
| uncurable | = | inconsolabilis |
| uncured | = | incuratus |
| undamaged | = | integer |
| undaunted | = | imperterritus, animosus, intrepidus |
| unddistinguished | = | inglorius |
| undecided | = | irritus |
| undefeated | = | invictus |
| under | = | infra (+ acc.), inferus, sub (+ acc. or dat.), sub |
| under an obligation | = | obligatus |
| under compulsion | = | coactu |
| under oath | = | iuratus |
| under, be - | = | subsum subesse |
| undergo (vb) | = | luo, suscipere |
| undermine (vb) | = | subruo subruti subrutum |
| underneath | = | subter supter, infra (adv.) |
| understand (vb) | = | intellego intellexi intellect, deprehendo |
| understand | = | verto, teneo, percipio percepi perceptum, scio |
| understanding | = | lumen, sensus, intellectus |
| undertake (vb) | = | conor, invado |
| undertake | = | adeo, coepio, promitto, promitto, coepto, ineo |
| undertake again | = | retracto |
| undertaker | = | vespillo |
| undertaking | = | coeptum, commissum, orsus, conatus |
| undertook | = | coepi |
| underworld | = | barathrum |
| underworld | = | orcus |
| undestroyed | = | inconvulsus |
| undigested | = | crudus |
| undiminished | = | inconsumptus |
| undisputably | = | quiete |
| undistinguished | = | modicus, modica |
| undisturbed | = | quietus |
| undo | = | laxo, explico |
| undomesticated | = | efferus |
| undone, be - (vb) | = | intereo |
| undoubted | = | certus |
| undoubtedly | = | certe, nimirum |
| undulate | = | undo |
| uneasiness | = | sollicitudo |
| uneasy | = | sollicitus, anxia |
| uneasy, make (vb) | = | anxio |
| unequal | = | iniquus |
| unexamined | = | incognitus |
| unexpected | = | improviso, repentina, repens, insperatus, subitus |
| unexpectedly | = | insperate, subito, repente |
| unexplainable | = | inedicabilis |
| unfading | = | immarcescibilis |
| unfair | = | iniquus, iniustus |
| unfairly | = | inique |
| unfairness | = | iniquitas |
| unfaithful | = | infidelis |
| unfavorable | = | adversa, importunus |
| unfeeliing | = | ferreus |
| unfinished | = | infectus, inchoatus |
| unfit | = | indignus |
| unfit for man or beast | = | inhabitabilis |
| unfitting | = | inopportunus |
| unfixed | = | irritus |
| unfold (vb) | = | explico |
| unfortunate | = | adversus (adj.), miser, infortunatus |
| unfrequented places | = | devia |
| unfruitful | = | infructuosus, infelix |
| ungodly | = | impius |
| ungrateful | = | ingratus |
| ungratefully | = | ingrate ingratiis ingratis |
| unhappily | = | infeliciter |
| unhappy | = | infortunatus |
| unharmed | = | incolumis, illaesus, sospes |
| unharnass (vb) | = | abiungo |
| unhealed | = | incuratus |
| unhesitatingly | = | incunctanter |
| unhurt | = | salvus, integer |
| uniformity | = | similitudo |
| unimpeded | = | expeditus, licens |
| unimpotant | = | levis |
| unimproved | = | incorrectus |
| uninhabitable | = | inhabitabilis |
| uninitiated | = | profanus |
| uninjured | = | incolumis |
| uninterrupted | = | continuus, perennis, perpetuus, continuus |
| uninterrupted course | = | tenor |
| union | = | conspiratio, iugum, congregatio, conventus |
| unique | = | singularis |
| unite (vb) | = | conjugo, conjungo |
| unite | = | iungo iunxi iunctum, comprehendo, concilio |
| unite by an oath (vb) | = | conjuro |
| united | = | concordis |
| united | = | iunctus |
| uniting | = | coadunatio |
| unity | = | concordia |
| universal | = | omnimodus |
| universe | = | universum, mundus, universitas |
| university | = | universitas |
| unjust | = | iniquus, iniustus |
| unjustifiably | = | immerito |
| unkempt | = | incomptus |
| unknowing | = | insciens |
| unknown , be - (vb) | = | latet |
| unknown | = | incognitus, incompertus, imperceptus, ignotus |
| unkowing, be - | = | nescio |
| unlamented | = | infletus |
| unlawful | = | illicitus |
| unless | = | nisi |
| unlike | = | diversus, dissimilis |
| unlike one's kind , be - (vb) | = | degenero |
| unlimited | = | infinitus |
| unlooked for | = | insperatus |
| unloose (vb) | = | persolvo |
| unlucky | = | infortunatus, laevus levus |
| unman | = | castro |
| unmanageable | = | inhabilis |
| unmannered | = | agrestis (adj) |
| unmarried | = | agamus, cælebs |
| unmixed | = | putus |
| unmotivated | = | desidiosus |
| unmourned | = | infletus |
| unmoved | = | immotus |
| unnatural | = | prodigiosus |
| unnatural thing | = | prodigium |
| unnecessary | = | supervacuus |
| unofficial | = | privatus |
| unpassable | = | impervius |
| unpatriotic | = | impius |
| unperceived | = | imperceptus |
| unplanned | = | inconditus |
| unpleasant | = | incommodus, ingratus, incommodo (-are) |
| unpleasantness | = | ruta |
| unpolished | = | incultus |
| unpolluted | = | incontaminatus, castitas |
| unprepared food | = | crudus |
| unproduction | = | infructuosus |
| unproductive | = | infelix, sterilis, inefficax |
| unpropitious | = | laevus levus |
| unpunished | = | impunitus, inultus |
| unravel | = | extrico |
| unrecognized | = | incognitus |
| unrelated | = | extrarius |
| unreliable | = | inconstans, volaticus |
| unremitting | = | assiduus |
| unrestrained | = | effrenus, laxe, impunitus, licens |
| unrestricted | = | liber libera, liberum |
| unrewarded | = | inhonoratus |
| unripe | = | crudus, crudus |
| unroll | = | explico |
| unroll a book (vb) | = | revolvo |
| unseemly | = | dedecor, turpis |
| unseemly event | = | inopportunitas |
| unshaken | = | intrepidus, inconcussus |
| unshattered | = | inconvulsus |
| unskilled | = | iners |
| unstrained | = | incontentus |
| unstretched | = | incontentus |
| unsuitable | = | importunus, incongruus, importunus |
| unsuited | = | inhabilis |
| unsupportably | = | intolerabiliter |
| unsure , be - (vb) | = | hesito (haesito) |
| unsure | = | incertus |
| untainted | = | incorruptus |
| untamed | = | indomitus, efferus, ferus |
| untamed spirit | = | ferocitas |
| untangle (vb) | = | evolvo |
| untasted | = | ingustatus |
| untended | = | incuratus |
| untidy | = | incultus |
| untie | = | solvo, divello |
| until | = | tenus, insquequo, donec, dum, donec |
| untilled | = | incultus, incultus |
| untimely | = | crudus |
| untouched | = | integer |
| untranslated | = | fidelis |
| untried | = | inexperta |
| untrimmed | = | incomptus |
| untru | = | infidus |
| untrue | = | infidelis |
| untuned | = | incontentus |
| unusual | = | novus, insolita, insolitus |
| unutterable | = | ineffabilis |
| unwarlike | = | imbellis |
| unwavering | = | constans |
| unwell | = | aegrus |
| unwept | = | infletus |
| unwholesome | = | gravis |
| unwilling | = | invitus, nolens |
| unwilling, be - (vb) | = | nolo |
| unwilling, be - | = | recuso |
| unwillingly | = | ingrate ingratiis ingratis |
| unworked | = | infectus |
| unworried | = | securus |
| unworthy | = | indignus |
| unyielding | = | adamans |
| up , become - (vb) | = | subolesco |
| up after , become - (vb) | = | succresco |
| up and down | = | sursum deorsum |
| up for sale | = | venalis |
| up to | = | tenus (after a name in abl. o |
| up to the time when | = | donec |
| up to then | = | eatenus |
| up to this point | = | hactenus |
| up to) | = | usque |
| up under | = | sub (+ acc. or dat.) |
| upheaval. | = | vexamen |
| uphold (vb) | = | tueor |
| uphold | = | fulcio |
| upper | = | optimates |
| upper | = | superus superior supremus or |
| upper arm | = | lacertus |
| upper arm | = | umerus humerus |
| uppermost | = | primoris |
| upright | = | probus, pius, ingenuus, erectus, rectus |
| uprightly | = | caste |
| uprightness | = | probitas |
| uprising | = | tumultus |
| uproar | = | tumultus, turba |
| upset | = | turbo, verto, commoveo |
| upwards | = | sursum |
| upwelling of emotion | = | effusio |
| urban | = | urbanus |
| urbane | = | urbanus |
| urge (vb) | = | compello |
| urge | = | instigo, incito, urgeo, insisto |
| urge on | = | impello impuli impulsum |
| urge or incite to action (vb) | = | admoneo |
| urgently | = | instanter |
| urine | = | urina |
| us | = | nos, nobis (dat.), nobis (abl.) |
| usage | = | consuetudo, mos, ritus |
| use | = | inhibeo, usio, fruor, commodum, utor, usurpo, usus |
| use a word incorrectly | = | abutor |
| use abusive language (vb) | = | abutor |
| use of something | = | ususfructus |
| use up | = | absumere, consumo, consumere, abuti |
| use with moderation | = | tempero (+ dat.) |
| used to | = | adsuesco assuesco |
| used to, be - | = | soleo |
| useful , be - (vb) | = | prosum (profuturus), prosum (with dat.) |
| useful | = | utilis, commodus |
| usefulness | = | utilitas |
| useless | = | vacuus, sterilis, inritus irritus, irritus, inanis |
| using | = | usura |
| using money lent | = | usura |
| usual | = | solitus, catholicus, consueta, vulgaris, usitas |
| usurp | = | invado, invado |
| uterus | = | uterus, volva, utriculus |
| utility | = | utilitas, utilitas |
| Utrecht | = | Traiectensium |
| utter | = | sono, effundo, dissero |
| utterance | = | proloquium, famen |
| utterly | = | radicitus, prorsus, funditus, prorsus |