The eradication of a foreign species, usually extraterrestrial in nature.

when you're hungover as shit after a spending a night drunk as a skunk

The act of a member of one species purposefully causing the extinction of another species.

The act of causing the complete extinction of an entire species.

Xenocide is genocide directed at an alien species.

Xenocide is 'killing the other', for example when a person targets Jews in a synagogue, or Gays in a gay bar.

It comes from the Greek word 'xeno' which means foreigner, and the Latin ending '-cide' to mean to kill, as in suicide.

Jus as the word xenophobia means the fear of outsiders, xenocide is the killing of people deemed to be outsiders.