- co-
- co- [kəu US kou] prefix[: Latin; Origin: 'together, with', from com-; COM-]1.) together with▪ to coexist (=exist together or at the same time)▪ coeducation (=with boys and girls together)2.) doing something with someone else as an equal or with less responsibility▪ my co-author (=someone who wrote the book with me)▪ the co-pilot (=someone who helps a pilot)
Dictionary of contemporary English. 2013.