1. penis — de Vaan
penis 'tail, penis' [m* i] (Naev.H-) Derivatives: penitus 'furnished with a tail' (Naev. apud Fest), peniculus 'brush, sponge' (¥\.+\ peniculamentum 'train (cff a garment)' (Enn.). Pit *petsni- 4tail\ It is generally assumed that penis directly reflects PIE *pes-ni- 'penis', as attested in Hit *pesan-I pesn- / pisen- 'man, male' [c] < *pes-dn, *pes-(e)n-\ Skt pasas- [n.], Gr. πέος [η.] 'penis' < *pes-os-; maybe also … — [de Vaan, s.v. penis, p. 472]