Added 10 October 2026 protosomite noun Categories: Obscure Words noun ! Definition from Wiktionary (CC BY-SA). More about protosomite at Wordnik → Where our words come from → One of the segments, or metameres, of an animal in its early stage of development. Origin From proto- + somite. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: protopoditeprotomeriteprosomiteprotistonmetamereprosomaprotopodiumprotomiteprotomontprotoscolexpropodiumprotostoma Back to today's word