pullulate
verb (formal)- [intransitive]
to breed (= produce young) or spread quickly 迅速繁殖；大量扩散 - [intransitive]
to be full of life or activity 充满生机；生机勃勃；生机盎然
Word Originearly 17th cent.: from Latin pullulat- ‘sprouted’, from the verb pullulare, from pullulus, diminutive of pullus ‘young animal’.