diatribe

diatribe \DAHY-uh-trahyb\, noun:

a bitter verbal attack or speech

It wasn't an argument, it was a diatribe. I've never seen anything like it. It's an insult to you (the jury).
-- J. Tony Serra

by 1581, from Latin diatriba "learned discussion," from Greek diatribe "discourse, study," literally "a wearing away (of time)," from dia- "away" + tribein "to wear, rub."