terra incognita (L.), an unknown country.
tertium quid (L.), a third something.
thalatta, thalatta! (Gr.), the sea, the sea! [the exulting cry of Xenophon's soldiers on catching sight of the sea].
timeo Danaos et dona ferentes (L.), I fear the Greeks, even when bringing gifts.
tirage à part (Fr.), an off-print, or article reprinted separately from the magazine, &c., in which it first appeared—the German Abdruck.
toga virilis (L.), the garb of manhood.
to kalon (Gr.), the beautiful: the chief good.
Tornacum (L.), Tournay.
totidem verbis (L.), in just so many words.
toties quoties (L.), as often as.