Real Dictionary

marinade
countable noun: A marinade is a sauce of oil, vinegar, spices, and herbs, which you pour over meat or fish before you cook it, in order to add flavour, or to make the meat or fish softer.
verb: To marinade means the same as to marinate.

marinade in American English
a spiced pickling solution, esp. a mixture of oil, wine or vinegar, and spices, in which meat, fish, etc. is steeped, often before cooking
marinate
noun: a seasoned liquid, usually of vinegar or wine with oil, herbs, spices, etc., in which meat, fish, vegetables, etc., are steeped before cooking
transitive verb: to marinate

marinade in British English
noun: a spiced liquid mixture of oil, wine, vinegar, herbs, etc, in which meat or fish is soaked before cooking
verb