[yoo-soh-shuh l]
adjective Animal Behavior.
  1. of or relating to a form of insect society, as that of ants, characterized by specialization of tasks and cooperative care of the young.

Origin of eusocial

First recorded in 1970–75; eu- + social
Related formseu·so·ci·al·i·ty [yoo-soh-shee-al-i-tee] /yuˌsoʊ ʃiˈæl ɪ ti/, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018