Where does “äkistä” come from?

äkistä (Finnish) comes from Finnish äkeä, from Finnish -ea, from Proto-Finnic -eda, from Proto-Uralic -eta — A generic adjective marker, attached to roots.

Ancestry of “äkistä”, step by step

StepLanguageWordMeaning
1Finnishäkeäirascible, irked, irritated, sullen
2Finnish-eaA suffix for making adjectives from some nouns...
3Proto-Finnic-edaA generic adjective marker
4Proto-Uralic-etaA generic adjective marker, attached to roots
Every word from Proto-Uralic -eta →Every word from Finnish -ea →Every word from Finnish äkeä →