primary sexual organ that male animals use to inseminate sexually receptive mates (females or hermaphrodites) during copulation, occurring in many (but not all) animals, including humans

A penis (plural penises or penes /-nz/) is the main sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation.[1] Such organs are found in many animals, both vertebrate and invertebrate, but males do not always have a penis in every species, and in those species in which the male does have a so-called penis, the penises in those species are not homologous.

The penis of an Asian elephant


  1. Janet Leonard; Alex Cordoba-Aguilar R (18 June 2010). The Evolution of Primary Sexual Characters in Animals. Oxford University Press. ISBN 978-0-19-971703-3. Archived from the original on 11 October 2013. Retrieved 20 July 2013.