Where does “obsesja” come from?

obsesja (Polish) comes from Latin obsessiō, from Latin obsidere, from Latin obsideo, from Latin ob-, from Latin obolus, from Ancient Greek ὀβολός, from Ancient Greek ὀβελός, from Ancient Greek βέλος — to throw, reach, pierce; to hit by throwing.

Ancestry of “obsesja”, step by step

Step	Language	Word	Meaning
1	Latin	obsessiō	—
2	Latin	obsidere	present active infinitive of obsideō;...
3	Latin	obsideo	I sit, remain, abide, stay; I frequent, haunt,...
4	Latin	ob-	towards; against
5	Latin	obolus	obolus
6	Ancient Greek	ὀβολός	obol, obolus, used at Athens as both a weight and...
7	Ancient Greek	ὀβελός	a spit, rod; a horizontal line
8	Ancient Greek	βέλος	missile, arrow, dart; weapon; something quickly...
9	Proto-Indo-European	gʷélHos	—
10	Proto-Indo-European	gʷelH-	to throw, reach, pierce; to hit by throwing

Every word from Proto-Indo-European gʷelH- →