Where does “грохвам” come from?

грохвам (Bulgarian) comes from Bulgarian -вам, from Proto-Slavic -ovati — Creates verbs out of nouns and adjectives.

грохвам (Bulgarian): to collapse, to crash down, to fall heavily usually from exhaustion, overwork, or loss of strength

Definitions

to collapse, to crash down, to fall heavily usually from exhaustion, overwork, or loss of strength

Step	Language	Word	Meaning
1	Bulgarian	-вам	Forms an imperfective partner verb, with the same meaning, from a perfective verb
2	Proto-Slavic	-ovati	Creates verbs out of nouns and adjectives