'common-origin' is a modern compound formed from the adjective 'common' and the noun 'origin'. 'common' originates from Old French 'comun', ultimately from Latin 'communis', where the element 'com-' meant 'together' and 'munis' related to 'service/obligation' (giving the sense 'shared'). 'origin' originates from Latin 'origo' (genitive 'originis'), where 'origo' meant 'beginning' or 'source'.

'common-origin' combined the modern English words 'common' and 'origin'. 'common' entered English via Old French 'comun' from Latin 'communis'; 'origin' came into English via Old French 'origine' from Latin 'origo/originis' and through Middle English became 'origin'. Over time these component words preserved their meanings and were compounded in modern English to describe a shared source.

Initially, the components meant roughly 'shared' ('common') and 'beginning/source' ('origin'); combined as a compound the term has retained that combined sense of a 'shared beginning' or 'shared source'.