con-

Forms

• con-
• com- — Used before certain consonants, especially b, p, and m.
• col- — The final consonant changed before l.
• cor- — The final consonant changed before r.
• co- — The final consonant was lost in some combinations.

Origin

From Latin cum, “with,” and an older form com-.

Note

Togetherness could extend to completeness. Not every word containing this prefix retains an obvious “with” meaning.