Where does “infīlāre” come from?

infīlāre (Latin) comes from Latin fīlum, from Proto-Italic fī(s)lom, from Proto-Indo-European gʷʰiH-(s-)lo-.

Ancestry of “infīlāre”, step by step

Step	Language	Word	Meaning
1	Latin	fīlum	—
2	Proto-Italic	fī(s)lom	—
3	Proto-Indo-European	gʷʰiH-(s-)lo-	—