Pronunciation: (pru-lif'ik),[key] —adj. 1. producing offspring, young, fruit, etc., abundantly; highly fruitful: a prolific pear tree. 2. producing in large quantities or with great frequency; highly productive: a prolific writer. 3. profusely productive or fruitful (often fol. by in or of): a bequest prolific of litigations. 4. characterized by abundant production: a prolific year for tomatoes.