Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

1. O, o, the fourteenth letter of the Latin alphabet, corresponding to the Gr. ο and ω. The Latin language possessed both the sound and the sign from the earliest times; whereas the Etruscan language never possessed the o, and the Umbrian seems not to have received it as an alphabetical character till a later period. The oldest monuments of the Latin tongue frequently employ o where the classic language has u. So on the Column. Rostr. MACESTRATOS (acc. plur.), EXFOCIONT, CONSOL, PRIMOS (nom. sing.), CAPTOM; in the epitaphs of the Scipios, HONC OINO, COSENTIONT, DVONORO OPTVMO VIRO (bonorum optumum virum); in the S. C. de Bacch. IN OQVOLTOD al. And even in the later inscrr. and MSS., we sometimes find o for u: POPLICO, POPOLVM, TABOLEIS, in the Tab. Bantina: FACIONDAM DEDERONT, Inscr. Orell. 1585: MONDO, HOC TOMOLO, ib. 4858: fondus, fornacatibus, solitodo, etc., in good MSS. (v. Freund, Cic. Mil. p. 18). And, on the contrary, u for o in the old forms, fruns, funtes, for frons, fontes, v. h. vv.: RVBVSTIS for robustis, in the Cenot. Pisan.; v. Inscr. Orell. 642: NVMENCLATOR, Inscr. Grut. 630, 5: CONSVBRINVS, ib. 1107, 1: SACERDVS, ib. 34, 5: VNV LOCV, ib. 840, 1. O appears in class. Lat. particularly in connection with qu and v: quom, avos. This interchange of o and u seems to have been effected rather by dialectical and local than by organic and historical causes; just as in the modern Italian dialects a preference is shown on the one hand for o and on the other for u, and in one and the same dialect the Latin o has passed over into u and the u into o.
On the commutation of o and e, see the letter E.
We have o for au in Clodius, plodo, plostrum, sodes, etc. (also in polulum for paululum, Cato, R. R. 10, 2).
O inserted in the archaic forms: Patricoles, Hercoles, v. Ritschl ap. Rhein. Mus. 8, p. 475 sq., and 9, p. 480. As an abbreviation, O. stands for omnis and optimus: I. O. M., Jovi Optimo Maximo: O. E. B. Q. C., ossa ejus bene quiescant condita, Inscr. Orell. 4489; cf.: O. I. B. Q., ossa illius bene quiescant, ib. 4483; 4490: O. N. F., omnium nomine faciundae, ib. 4415: O. T. B. Q., ossa tua bene quiescant: O. V., optimo viro, ib. 4135; also: optimi viri, ib. 5037.

2. ō (long also before an initial vowel: o ego, Ov. M. 8, 51; Hor. A. P. 301; but also short: ŏ Alexi, Verg. E. 2, 65), interj. The commonest exclamation of joy, astonishment, desire, grief, indignation, etc.; O! Oh! constr. usually with voc. or acc.; less freq. with nom., gen., utinam, si.

    1. 1. With voc.: o Romule, Romule die, Enn. ap. Cic. Rep. 1, 41 Vahl. (Ann. v. 115 Vahl.): o Tite, tute Tuti, id. ap. Prisc. p. 947 P. (Ann. v. 113 Vahl.); cf.: o Tite, si quid te adjuero, id. ap. Cic. Sen. 1, 1 (Ann. v. 339 Vahl.): o mi Furni! Cic. Fam. 10, 26, 2: o paterni generis oblite, id. Pis. 26, 62.
    2. 2. With acc.: o faciem pulchram … o infortunatum senem, Ter. Eun. 2, 3, 5 and 7: o miseras hominum mentes, Lucr. 2, 14: o me perditum, o me afflictum! Cic. Fam. 14, 4, 3: o hominem nequam! id. Att. 4, 13, 2: o praeclarum custodem ovium, ut aiunt, lupum! id. Phil. 3, 11, 27: o rem totam odiosam, id. Att. 6, 4, 1: o Bruti amanter seriptas, litteras, id. ib. 15, 10.
    3. 3. With nom. (rare): o pietas animi, Enn. ap. Cic. Ac. 2, 27, 88 (Ann. v. 8 Vahl.): o Patricoles, id. ap. Cic. Tusc. 2, 16, 38 (Trag. v. 14 Vahl.): o vir fortis atque amicus! Ter. Phorm. 2, 2, 10: o ego ter felix, Ov. M. 8, 51; so, o ego, Hor. A. P. 301: o multum miseri, Ov. M. 4, 155: o qualis facies! Juv. 10, 157.
    4. 4. With utinam: o utinam Obrutus esset! Ov. H. 1, 5; id. M. 1, 363 al.
    5. 5. With si: quamquam, o si solitae quicquam virtutis adesset! yet oh! if, etc., Verg. A. 11, 415.
    6. 6. With gen.: o nuntii beati, Cat. 9, 5.
      By poets also placed after a word: o lux Dardaniae, spes o fidissima Teucrūm, Verg. A. 2, 281: quid o tua fulmina cessant! Ov. M. 2, 279.
      Three times repeated: o pater, o genitor, o sanguen dis oriundum, Enn. ap. Cic. Rep. 1, 41 (Ann. v. 117 Vahl.); cf.: o pater, o patria, o Priami domus, id. ap. Cic. Tusc. 3, 19, 44 (Trag. v. 118 Vahl.): o soror, o conjux, o femina sola superstes, Ov. M. 1, 351.