T, t. indecl. n. or (to agree with littera) f., the nineteenth letter of the Lat. alphabet (i and j being counted as one), = Gr. T (t). It is very freq. as a final letter, esp. in verbal endings of the third person. I. As an initial, it is, in pure Lat. words, followed by no consonant except r: traho, tremo, tribuo, etc.; the combinations tl and tm are found only in words borrowed from the Greek: Tlepolemus, tmesis, Tmolus. Hence an initial t occurring in the ancient language before l (like an initial d before v, v. letter D) is rejected in classical Lat.: lātus (Part. of fero) for tlatus, from root tol- of tollo, tuli; cf. with *t*l*a*w, tlhto/s; even when softened by a sibilant, the combination of t and l in stlata (genus navigii), stlembus (gravis, tardus), stlis, stlocus, was avoided, and, except in the formal lang. of law, which retained stlitibus judicandis, the forms lis, locus remained the only ones in use, though the transitional form slis occurs twice in very old inscriptions. Before a vowel or r, the original Indo-European t always retained its place and character. Between two vowels t and tt were freq. confounded, and in some words the double letter became established, although the original form had but one t; thus, quattuor, cottidie, littera, stand in the best MSS. and inscriptions; v. Corss. Ausspr. 1, 174 sqq.—II. The sibilant pronunciation of a medial t before i and a following vowel, is a peculiarity of a late period. Isidorus (at the commencement of the seventh century after Christ) is the first who expresses himself definitely on this point: cum justitia sonum z litterae exprimat, tamen quia Latinum est, per t scribendum est, sicut militia, malitia, nequitia et cetera similia (Orig. 1, 26, 28); but the commutation of ci and ti, which occurs not unfrequently in older inscriptions, shows the origin of this change in pronunciation to have been earlier. In the golden age of the language, however, it was certainly unknown.—III. The aspiration of t did not come into general use till the golden age; hence, CARTACINIENSIS, on the Columna Rostrata; whereas in Cicero we have Carthago, like Cethegus, etc.; v. Cic. Or. 48, 160; and cf. letter C.—IV. T is interchanged with d, c, and s; v. these letters.—V. T is assimilated to s in passus from patior, quassus from quatio, fassus from fateor, missus from mitto, equestris from eques (equit-), etc. It is wholly suppressed before s in usus, from utor; in many nominatives of the third declension ending in s: civitas (root civitat, gen. civitatis), quies (quiet, quietis), lis (lit, litis), dos (dot, dotis), salus (salut, salutis), amans (amant, amantis), mens (ment, mentis), etc.; and likewise in flexi, flexus, from flecto, and before other letters, in remus, cf. ratis; Gr. e)retmo/s; in penna; root pat-, to fly; Gr. pe/tomai, etc. In late Lat. the vulgar language often dropped t before r and before vowels; hence such forms as mari, quaraginta, donaus, are found for matri, quatriginta (quad-), donatus, in inscriptions; cf. the French mère, quarante, donné.—VI. As an abbreviation, T. stands for Titus; Ti. Tiberius; TR. Tribunus; T. F. Testamenti formula; T. F. C. Titulum faciendum curavit; T. P. Tribunicia potestas, etc.