Relating to or denoting leguminous plants of a group (subfamily "Papilionoideae" or family "Papilionaceae") with flowers that resemble a butterfly.
- ‘The flowers have a typical papilionaceous corolla.’
- ‘Flowers of normal plants are typically papilionaceous with a large standard petal, two free-wing petals, and two fused-keel petals.’
- ‘The corolla of Trigonellinae is typically papilionaceous, comprising a standard petal, two wing petals and a keel made up of two marginally fused petals.’
Mid 17th century: from modern Latin Papilionaceae (plural), based on Latin papilio butterfly + -ous.