fer·til·ize (BrE also-ise) [fertilizefertilizesfertilizedfertilizing] BrE [ˈfɜːtəlaɪz] NAmE [ˈfɜːrtəlaɪz] verb 1.~ sth to put ↑pollen into a plant so that a seed develops; to join ↑sperm with an egg so that a baby or young animal develops •Flowers are often fertilized by bees as they gather nectar. •a fertilized egg 2.~ sth to add a substance to soil to make plants grow more successfully Derived Word: ↑fertilization Verb forms: