Where does “filament” come from?

filament (French) comes from Medieval Latin filamentum, from Late Latin filo, from Latin fīlum, from Proto-Italic fī(s)lom, from Proto-Indo-European gʷʰiH-(s-)lo-.

Ancestry of “filament”, step by step

Step	Language	Word	Meaning
1	Medieval Latin	filamentum	—
2	Late Latin	filo	to spin, draw out in a long line; dative singular...
3	Latin	fīlum	—
4	Proto-Italic	fī(s)lom	—
5	Proto-Indo-European	gʷʰiH-(s-)lo-	—

Every word from Proto-Indo-European gʷʰiH-(s-)lo- →

filament — Etymology, Origin & Word History | Etymology Explorer