1. Together; joint; jointly; mutually: coeducation.
a. Partner or associate in an activity: coauthor; cofounder.
b. Subordinate or assistant: copilot.
3. To the same extent or degree: coextensive.
4. Complement of an angle: cotangent.
[Middle English, from Latin, variant of com-, com-.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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