/ gəˈrɪlə; NAmE / noun
1.
a very large powerful African ape (= an animal like a large monkey without a tail) covered with black or brown hair
2.
( informal ) a large aggressive man
••
WORD ORIGIN
from an alleged African word for a wild or hairy person, found in the Greek account of the voyage of the Carthaginian explorer Hanno in the 5th or 6th cent. BC; adopted in 1847 as the specific name of the ape.