n. 合作者, 合伙人, 同犯

[经] 合伙人

[ noun ]
a joint partner (as in a business enterprise)
<noun.person>

Copartner \Co*part"ner\, n.
One who is jointly concerned with one or more persons in
business, etc.; a partner; an associate; a partaker; a
sharer.

the associates and copartners of our loss. --Milton.