Fornander:
"PI, v. Haw., to sprinkle, as water; to throw water with the hand; pi-pi, ka-pi, id.
Sam., pi, to splash, slap, as a fish in a trap; ta-pi, rinse with fresh water; pisi, to splash with water.
Tah., pi-pi, sprinkle with water.
Sanskr., pi = pā, to drink; piv, id.; pinu, to sprinkle; pitha, a drink, water; pipāsā, thirst.
Greek, πινω, to drink; πιστρα, a drinking trough, drink, water; πιπισκω, give to drink; πωμα, drink, liquor, &c.
Lat., bibo, to drink; bibulus, potus.
Slav., pi, piti, pivati, to drink.
The transition from the sense conveyed in the Polynesian to that in the West Aryan tongues will be intelligible to those who have observed the manner of drinking which probably obtained before cups or containers were used, and which is still very common among the Polynesians when travelling; it is by 'throwing the water with the hand' from the spring or river to the mouth. That primary sense seems to have survived in the Sanskrit pinu, to sprinkle."