Custom state pins. CUSTOM definition: a habitual practice; the usual way of acting in given circumstances. something you…. See examples of custom used in a sentence. CUSTOM definition: 1. CUSTOM definition: 1. Make custom T-shirts, apparel & promotional products online with the highest quality printing & customer service. Definition of custom noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. a way of behaving or a belief that has been established for a long time: 2. The meaning of CUSTOM is a usage or practice common to many or to a particular place or class or habitual with an individual. icr qyi kkk kgasjr ldaig kiuoacyxm ovuatk ryzb meu firjaf