Where does “pretty” come from?

Pretty comes from Middle English prety, from Old English prættiġ, from Proto-Germanic prattugaz, ultimately from Proto-Indo-European -kos.

pretty (English): Pleasant to the sight or other senses;...

Definitions

Step	Language	Word	Meaning
1	Middle English	prety	—
2	Old English	prættiġ	tricky, crafty, sly, cunning, wily, astute
3	Proto-Germanic	prattugaz	boastful, sly, slick, deceitful, tricky, cunning
4	Proto-Germanic	-gaz	-y
5	Proto-Indo-European	-ḱos	-y, -ic

pretty — Etymology, Origin & Word History | Etymology Explorer