over- (from the lat. super- ) 1 Prefix that expresses increase or reinforcement, superior position or the time that happens to the thing expressed by the name: overproduction, bonus, childbirth, after-dinner . As you can see in the 12th Accept. of on , with the last meaning is also written separately. 2 In front of a verb, in expressions that are already unused, express lightly or above : Sobrebarrer .