Marinate means to soak food in a seasoned liquid, usually an acidic one like vinegar or lemon juice. The purpose is to add flavor and tenderize the meat by breaking down its fibers.
It is delicious as soon as you make it, but I've found that letting in marinate in the refrigerator for a few hours intensifies the flavors and makes it even better! (wellnessmama.com)
The concept of marinating chicken in a spicy fruit juice and then char - broiling originated in Mexico and is becoming quite popular throughout the Southwest. (fieryfoodscentral.com)