Where does “sḱl̥-” come from?

sḱl̥- (Proto-Indo-European) comes from Proto-Indo-European skel-, from Proto-Indo-European kel- — to hit; beat; to pierce, to stab; goblet.

Ancestry of “sḱl̥-”, step by step

sḱl̥- traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Proto-Indo-European	skel-	to be obligated, owe; to be guilty
2	Proto-Indo-European	kel-	to hit; beat; to pierce, to stab; goblet

Step	Language	Word	Meaning
1	Proto-Indo-European	sḱel-	to be obligated, owe
2	Proto-Indo-European	ḱelh₁-	to warm up, to be hot; to warm up, be hot