What does co mean in a word like co-worker or co-operative?

The prefix "co-" in words like "co-worker" and "co-operative" comes from the Latin word "cum," which means "with" or "together".

Therefore, "co-" indicates joint action, collaboration, or shared participation.

For example:

* Co-worker: Someone who works with you.

* Co-operative: An organization that is jointly owned and run by its members.

* Co-ordinate: To work together to achieve a common goal.

The prefix "co-" helps to emphasize that the action or entity involves multiple parties working together.