Where does “pikeytyä” come from?

pikeytyä (Finnish) comes from Finnish piki, from Old Swedish bik, from Middle Low German pik, from Old Saxon pik, from Proto-West Germanic *pik, from Latin pix, from Proto-Indo-European pik-, from Proto-Indo-European pi- — sap, juice.

pikeytyä (Finnish): to become pitchy, to become filled or covered with pitch