If you marinate meat or fish, or if it marinates, you keep it in a mixture of oil, vinegar, spices, and herbs, before cooking it, so that it can develop a special flavour. Marinate the chicken for at least 4 hours Put it in a screw-top jar with French dressing and leave to marinate. to put meat or fish in a marinade, or to be left in a marinade for some time marinate (sth) in sth (past participle of marinare , from marinus; MARINE)