quid_pro_quo
1. [ noun ] (business) something for something; that which a party receives (or is promised) in return for something he does or gives or promises
Synonyms: quid
Related terms: retainer
2. [ noun ] (business) an equal exchange
Synonyms: trade swap swop barter
Examples:

"we had no money so we hd to live by barter"

Related terms: exchange horse_trade trade barter