IPA: /ˈdaɪətraɪb/
KK: /ˈdaɪətraɪb/
A long and angry speech or piece of writing that criticizes someone or something very strongly.
The politician's diatribe against his opponents was filled with harsh accusations.
Diatribe is formed from "dia-" (meaning through or across) and "tribein" (Greek for to rub or wear away). The word originally referred to a discourse or a way of wearing down an argument through criticism or debate.
Think of 'going through' ('dia-') a process of 'rubbing away' ('tribein') someone's argument — that's why diatribe means a forceful criticism.