Where does “piar” come from?

piar (Galician) comes from Old Portuguese piar, from Vulgar Latin pilare, from Latin pila, from Latin pīlus, from Latin pīlum, from Proto-Italic pistlom, from Proto-Indo-European pis-tlo-, from Proto-Indo-European peys- — to grind, to crush.

piar (Galician): to tweet, to chirp; to covet; to ask; to speak;...