- variant of com- before a vowel, h, and gn: coadjutor; cohabit; cognate. The prefix co- now productively forms new words from bases beginning with any sound (co-conspirator; co-manage; coseismic), sometimes with the derived sense “auxiliary, subsidiary” (coenzyme; copilot), and, in mathematics and astronomy, with the sense “complement” (codeclination).
- together; joint or jointly; mutual or mutuallycoproduction
- indicating partnership or equalitycofounder; copilot
- to the same or a similar degreecoextend
- (in mathematics and astronomy) of the complement of an anglecosecant; codeclination
Word Origin and History for co-
in Latin, the form of com- in compounds with stems beginning in vowels and h- and gn- (see com-). Taken in English from 17c. as a living prefix meaning "together, mutually, in common," and used promiscuously with native words and Latin-derived words not beginning with vowels, sometimes even with words already having it (e.g. co-conspiritor).
- Together; joint; jointly; mutually:coaptation.
- Subordinate or auxiliary:coenzyme.
- To the same extent or degree:codominant.