Entry 1 sense Webster, 1913 Costermonger /(k?s"t?r-m?n`g?r)/ · Cos·ter·mon·ger · IPA 01 n. An apple seller; a hawker of, or dealer in, any kind of fruit or vegetables; a fruiterer. 1. An apple seller; a hawker of, or dealer in, any kind of fruit or vegetables; a fruiterer.