v.intr. 1 (of a seed, shoot, etc.) bud, sprout, germinate. 2 (esp. of an animal) swarm, throng; breed prolifically. 3 develop; spring up; come to life. 4 (foll. by with) abound. pullulant adj. pullulation n.
[ L pullulare sprout f. pullulus dimin. of pullus young of an animal ]