caramelize. verb car·a·mel·ize \-mə-ˌlīz\. Tweet. : to cook (something, such as a fruit or vegetable) slowly until it becomes brown and sweet.ull Definition of CARAMELIZE. transitive verb. : to change (as sugar) into caramel. intransitive verb. : to change to caramel. See caramelize defined for English-language learners. ADVERTISEMENT.