noun Download 🔗Share Any whale of family Balaenopteridae, with longitudinal skin folds running from below the mouth to the navel, allowing the capacity of the mouth to expand greatly when feeding. Examples : "While whale-watching, we learned that the rorqual, with its expandable throat pleats, can gulp down enormous schools of fish in one mouthful. " animal biology organism ocean nature Chat with AIVocabulary GamePractice Reading