Where does “геройство” come from?

геройство (Russian) comes from Russian геро́й, from French héros, from Latin hērōs, from Ancient Greek ἥρως, from Proto-Indo-European sēr-, from Proto-Indo-European ser- — to flow; to guard; to bind, to tie together.

геройство (Russian): heroism

Definitions

heroism

Ancestry of “геройство”, step by step

Step	Language	Word	Meaning
1	Russian	геро́й	hero
2	French	héros	hero
3	Latin	hērōs	demigod, hero
4	Ancient Greek	ἥρως	a hero of the Trojan War: any of the major...
5	Proto-Indo-European	sēr-	to flow
6	Proto-Indo-European	ser-	to flow; to guard; to bind, to tie together

Every word from Proto-Indo-European ser- →Every word from Proto-Indo-European sēr- →Every word from Ancient Greek ἥρως →