Definition of labellum in English:



  • 1Entomology
    Each of a pair of lobes at the tip of the proboscis in some insects.

  • 2Botany
    A central petal at the base of an orchid flower, typically larger than the other petals and of a different shape.

    • ‘If insects smaller than the pollinator become trapped they may crawl out without pollination occurring or, if larger than the pollinator, they may stay trapped until the labellum opens again.’
    • ‘The males then try to mate with the labellum or else lift it as they would a female wasp.’
    • ‘In attempting unsuccessfully to couple with the labellum the male pushes its head forward below the overhanging column.’
    • ‘The petals are lesser segments that typically envelop the column; the labellum is also generally small.’
    • ‘These encounters can be quite violent and frequently result in the labellum being torn from the flower.’


Early 19th century: from Latin, diminutive of labrum ‘lip’.