Where does “cliath” come from?

cliath (Middle Irish) comes from Proto-Celtic *kleitā, from Proto-Indo-European ḱley-, from Proto-Indo-European ḱel- — to cover; to incline.

Ancestry of “cliath”, step by step

Step	Language	Word	Meaning
1	Proto-Celtic	*kleitā	—
2	Proto-Indo-European	ḱley-	to shelter, cover; to lean, slope, incline
3	Proto-Indo-European	ḱel-	to cover; to incline

cliath — Etymology, Origin & Word History | Etymology Explorer