B, b, indecl. n., designates, in the Latin alphabet, the soft, labial sound as in English, unlike the Gr. beta (B, b), which approached the Engl. v in sound; v. Corss. Ausspr. I. p. 124 sqq. At the beginning of words it represents an original dv or gv, and elsewhere an original gv, p, v, or bh (v); v. Corss. Ausspr. I. pp. 134, 161. It corresponds regularly with Gr. b, but freq. also with p, and, in the middle of words, with f; cf. brevis, braxu/s; ab, a)po/; carbasus, ka/rpasos; ambo, a)mfi/, a)/mfw; nubes, ne/fos, etc.; v. Roby, Gram. I. p. 26; Kühner, Gram. 34, 6. In Latin, as in all kindred languages, it was used in forming words to express the cry of different animals, as balare, barrire, baubari, blacterare, boare, bombitare, bubere, bubulare; children beginning to talk called their drink bua; so, balbus denoted the stammering sound, bambalio the stuttering, blatire and blaterare the babbling, blaesus the lisping, blandus the caressing. At the beginning of words b is found with no consonants except l and r (for bdellium, instead of which Marc. Emp. also wrote bdella, is a foreign word); but in the middle of words it is connected with other liquid and feeble consonants. Before hard consonants b is found only in compounds with ob and sub, the only prepositions, besides ab, which end in a labial sound; and these freq. rejected the labial, even when they are separated by the insertion of s, as abspello and absporto pass into aspello and asporto; or the place of the labial is supplied by u, as in aufero and aufugio (cf. ab init. and au); before f and p it is assimilated, as suffero, suppono; before m assimilated or not, as summergo or submergo; before c sometimes assimilated, as succedo, succingo, sometimes taking the form sus (as if from subs; cf. abs), as suscenseo; and sometimes su before s followed by a consonant, as suspicor. When b belonged to the root of a word it seems to have been retained, as plebs from plebis, urbs from urbis, etc.; so in Arabs, chalybs ( = )/*aray, xa/luy), the Gr. y was represented by bs; as also in absis, absinthi-um, etc. But in scripsi from scribo, nupsi from nubo, etc., b was changed to p, though some grammarians still wrote bs in these words; cf. Prisc. pp. 556, 557 P.; Vel. Long. pp. 2224, 2261 ib. Of the liquids, l and r stand either before or after b, but m only before it, with the exception of abmatertera, parallel with the equally anomalous abpatruus (cf. ab init. and fin.), and n only after it; hence con and in before b always become com and im; as inversely b before n is sometimes changed to m, as Samnium for Sabinium and scamnum for scabnum, whence the dim. scabellum. B is so readily joined with u that not only acubus, arcubus, etc., were written for acibus, arcibus, etc., but also contubernium was formed from taberna, and bubile was used for bovile, as also in dubius ( = doio/s, duo) a b was inserted. B could be doubled, as appears not only from the foreign words abbas and sabbatum, but also from obba and gibba, and the compounds with ob and sub. B is reduplicated in bibo (cf the Gr. pi/w), as the shortness of the first syllable in the preterit bĭbi, compared with dēdi and stĕti or sti/ti, shows; although later bibo was treated as a primitive, and the supine bibitum formed from it. Sometimes before b an m was inserted, e. g. in cumbo for cubo ku/ptw, lambo for la/ptw, nimbus for ne/fos; inversely, also, it was rejected in sabucus for sambucus and labdacismus for lambdacismus. As in the middle, so at the beginning of words, b might take the place of another labial, e. g. buxis for pyxis, balaena for fa/laina, carbatina for carpatina, publicus from poplicus, ambo for a)/mfw; as even Enn. wrote Burrus and Bruges for Pyrrhus and Phryges; Naev., Balantium for Palatium (v. the latter words, and cf. Fest. p. 26).—In a later age, but not often before A.D. 300, intercourse with the Greeks caused the pronunciation of the b and v to be so similar that Adamantius Martyrius in Cassiod. pp. 22952310 P., drew up a separate catalogue of words which might be written with either b or v. So, Petronius has berbex for verbex, and in inscrr., but not often before A. D. 300, such errors as bixit for vixit, abe for ave, ababus for abavus, etc. (as inversely vene, devitum, acervus, vasis instead of bene, debitum, acerbus, basis), are found; Flabio, Jubentius, for Flavio, Juventius, are rare cases from the second century after Christ.—The interchange between labials, palatals, and linguals (as glans for ba/lanos, bilis for fel or xolh/) is rare at the beginning of words, but more freq. in the middle; cf. tabeo, th/kw, and Sanscr. tak, terebra and te/retron, uber and ou)=qar; besides which the change of tribus Sucusana into Suburana (Varr. L. L. 5, 48 Müll.; Quint. 1, 7, 29) deserves consideration. This interchange is most freq. in terminations used in forming words, as ber, cer, ter; brum or bulum, crum or culum, trum, bundus and cundus; bilis and tilis, etc.—Finally, the interchange of b with du at the beginning of words deserves special mention, as duonus for bonus, Bellona for Duellona, bellum for duellum, bellicus for duellicus, etc., and bis from duis.—As an abbreviation, B usually designates bonus or bene. Thus, B. D. = Bona Dea, Inscr. Orell. 1524; 2427; 2822: B. M. = bene merenti, ib. 99; 114; 506: B. M. P. = bene merenti posuit, ib. 255: B. D. S. M. = bene de se meritae, ib. 2437: B. V. V. = bene vale valeque, ib. 4816: B. M. = bonae memoriae, ib. 1136; 3385: B. M. = bonā mente, ib. 5033; sometimes it stands for beneficiarius, and BB. beneficiarii, ib. 3489; 3868; 3486 al.