T (tē), the twentieth letter of the English alphabet, is a nonvocal consonant. With the letter h it forms the digraph th, which has two distinct sounds, as in thin, then. See Guide to Pronunciation, §§262-264, and also §§153, 156, 169, 172, 176, 178-180.[1913 Webster]
The letter derives its name and form from the Latin, the form of the Latin letter being further derived through the Greek from the Phœnician. The ultimate origin is probably Egyptian. It is etymologically most nearly related to d, s, th; as in tug, duke; two, dual, L. duo; resin, L. resina, Gr. rhtinh, tent, tense, a., tenuous, thin; nostril, thrill. See D, S.[1913 Webster]
T bandage (Surg.), a bandage shaped like the letter T, and used principally for application to the groin, or perineum. -- T cart, a kind of fashionable two seated wagon for pleasure driving. -- T iron. (a) A rod with a short crosspiece at the end, -- used as a hook. (b) Iron in bars, having a cross section formed like the letter T, -- used in structures. -- T rail, a kind of rail for railroad tracks, having no flange at the bottom so that a section resembles the letter T. -- T square, a ruler having a crosspiece or head at one end, for the purpose of making parallel lines; -- so called from its shape. It is laid on a drawing board and guided by the crosspiece, which is pressed against the straight edge of the board. Sometimes the head is arranged to be set at different angles. -- To a T, exactly, perfectly; as, to suit to a T. [Colloq.][1913 Webster]