noun Download 🔗Share An outermost-but-one whorl of a flower, composed of petals, when it is not the same in appearance as the outermost whorl (the calyx); it usually comprises the petal, which may be fused. Examples : "The rose's vibrant red corolla of delicate petals surrounded its inner reproductive parts, contrasting sharply with the green sepals of its calyx. " plant biology part nature organism Chat with AIVocabulary GamePractice Reading