from The American Heritage® Dictionary of the English Language, 4th Edition
- Together; joint; jointly; mutually: coeducation.
- Partner or associate in an activity: coauthor; cofounder.
- Subordinate or assistant: copilot.
- To the same extent or degree: coextensive.
- Complement of an angle: cotangent.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- together; mutually; jointly
- partner or subordinate in an activity
- to the same degree
- of the opposite, of the counterpart
from the GNU version of the Collaborative International Dictionary of English
- A form of the prefix com-, signifying with, together, in conjunction, joint. It is used before vowels and some consonants. See com-.
Middle English, from Latin, variant of com-, com-.(American Heritage® Dictionary of the English Language, Fourth Edition)
From the Latin prefix co-. (Wiktionary)