. . . "Botany The flattened border of some stems, fruits, and seeds, or either one of the two side petals of certain flowers in the pea family.Origin of ala Latin ??la, wing. ala Noun (plural alae or al??)(zoology) A wing or winglike structure.(anatomy) A winglike anatomical process or part, especially of bone.(botany) The flattened border of some stems, fruits, and seeds, or one of the two side petals o" .