/tē/
1. [from LISP terminology for true] Yes. Used in reply to a question (particularly one asked using the -P convention). In LISP, the constant T means true, among other things. Some hackers use T and NIL instead of Yes and No almost reflexively. This sometimes causes misunderstandings. When a waiter or flight attendant asks whether a hacker wants coffee, he may well respond T, meaning that he wants coffee; but of course he will be brought a cup of tea instead. As it happens, most hackers (particularly those who frequent Chinese restaurants) like tea at least as well as coffee -- so it is not that big a problem.
2. See time T (also since time T equals minus infinity).
3. [techspeak] In transaction-processing circles, an abbreviation for the noun transaction.
4. [Purdue] Alternate spelling of tee.