keyboard warrior

[ kee-bawrd wawr-ee-er, wor‐, kee-bohrd ]
/ ˈkiˌbɔrd ˌwɔr i ər, ˌwɒr‐, ˈkiˌboʊrd /

noun Informal.

a person who posts highly opinionated text and images online in an aggressive or abusive manner, often without revealing his or her own identity.

Origin of keyboard warrior

First recorded in 2005–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019