'eusociality' originates from Greek and Latin, specifically the prefix 'eu-' from Greek meaning 'good' or 'well' and the Latin adjective 'socialis' meaning 'of companionship', with the noun-forming suffix '-ity'.

'eusociality' developed from the adjective 'eusocial' (a mid-20th century scientific coinage combining 'eu-' and 'social'), and the noun was formed by adding the suffix '-ity' to produce 'eusociality' in modern biological usage.

Initially formed from elements meaning 'well' or 'good' + 'companionship', the term evolved into a technical biological term meaning 'the highest level of social organization characterized by cooperative brood care, overlapping generations, and reproductive division of labor.'