Where does “высказаться” come from?

высказаться (Russian) comes from Russian вы́сказать, from Russian вы́-, from Old East Slavic вꙑ-, from Proto-Slavic vy-, from Proto-Balto-Slavic ū́, from Proto-Indo-European úd — out, outward.

высказаться (Russian): to express oneself, to express one's opinion;...

Definitions

to express oneself, to express one's opinion;...

Ancestry of “высказаться”, step by step

Step	Language	Word	Meaning
1	Russian	вы́сказать	to express (oneself), to say, to tell, to pronounce
2	Russian	вы́-	out, out from describing an action of moving outside from inside
3	Old East Slavic	вꙑ-	—
4	Proto-Slavic	vy-	out
5	Proto-Balto-Slavic	ū́	—
6	Proto-Indo-European	úd	out, outward

Every word from Proto-Indo-European úd →Every word from Russian вы́- →Every word from Proto-Balto-Slavic ū́ →