Where does “gliier” come from?

gliier (Old French) comes from Frankish glīdan, from Proto-Germanic glīdaną, from Proto-Indo-European ǵʰleydʰ- — to glide.

Ancestry of “gliier”, step by step

Step	Language	Word	Meaning
1	Frankish	glīdan	to slide, glide; to glide, to slide
2	Proto-Germanic	glīdaną	to glide; slide
3	Proto-Indo-European	ǵʰleydʰ-	to glide

gliier — Etymology, Origin & Word History | Etymology Explorer