Abstract: it is argued that Latin prōsāpia ‘lineage, stock’ together with sōpiō, -ōnis ‘penis’ goes back to the verbal root found in Vedic sāpáyati ‘to strike’, Ossetic safyn (I.), isafun (D.) ‘to destroy’, Hittite šap(p)- ‘to hit’ and Greek ἰάπτειν ‘to hurt’. The root can be reconstructed as *seh2p- (aor. *seh2p- > Hittite šapp-, pres. *se-seh2p- > Greek ἰάπτω). This root with the basic meaning ‘to hit, to strike’ was also employed metaphorically in the meaning ‘to have sexual intercourse’ which survives in Latin and Iranian (e.g. Balochi šāpag ‘to mount ewe’).