gorilla

Concise Oxford English Dictionary © 2008 Oxford University Press:
gorilla/ɡəˈrɪlə/

▶noun

• 1 a powerfully built great ape of central Africa, the largest living primate. [Gorilla gorilla.]

• 2 informal a heavily built, aggressive-looking man.

• 3 [with modifier] a dominant contender within a particular sphere of operation or activity: they'll be up against the 800-lb gorilla in this business, Sony.

– origin C19: from Gk, representing an alleged Afr. word for a wild or hairy person.