T 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.
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. "rhti`nh, tent, tense, a., tenuous, thin; nostril, thrill. See D, S.
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.]
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T
n 1: a base found in DNA (but not in RNA) and derived from
pyrimidine; pairs with adenine [syn: thymine]
2: one of the four nucleotides used in building DNA; all four
nucleotides have a common phosphate group and a sugar
(ribose) [syn: deoxythymidine monophosphate]
3: a unit of weight equivalent to 1000 kilograms [syn: metric
ton, MT, tonne]
4: a unit of information equal to a trillion
(1,099,511,627,776) bytes or 1024 gigabytes [syn: terabyte,
TB]
5: the 20th letter of the Roman alphabet
6: thyroid hormone similar to thyroxine but with one less
iodine atom per molecule and produced in smaller quantity;
exerts the same biological effects as thyroxine but is
more potent and briefer [syn: triiodothyronine, liothyronine]
7: hormone produced by the thyroid glands to regulate
metabolism by controlling the rate of oxidation in cells;
"thyroxine is 65% iodine" [syn: thyroxine, thyroxin, tetraiodothyronine]