co-

co- prefix. 

1. The prefix of co means "with".  It comes from Latin, where it has the meaning "joint, jointly, together.'' This meaning is found in such words as: co-star, coworker.

2. A similar meaning for this prefix is "auxiliary, helping.'' This meaning is found in such words as: co-pilot.

Word List

co-education

coexistence

co-author

coincidence

cooperate

coordinator

co-starring

co-writer

coappearing

cocomposer

codeveloper

co-inventors

co-counselled

co-dependency

co-sponsoring