'isogametic' originates from Greek combining form 'iso-' (from 'isos') meaning 'equal' and from Greek 'gamētēs' via New Latin 'gamete' meaning 'spouse' or 'marriage', with the English adjectival suffix '-ic'.

'isogametic' developed from the Greek root elements into New Latin/modern scientific usage as 'isogamete'/'isogametic' in biological literature and was adopted into English scientific vocabulary as 'isogametic'.

Initially it meant 'having equal (or similar) gametes'; this core meaning has been retained in modern biological usage.