[kawr-ni-kuh l]
  1. any of various small, horn-shaped processes, especially one of a pair of tubes at the posterior end of the abdomen of aphids, from which a waxy fluid is emitted.

Origin of cornicle

1640–50; < Latin corniculum little horn, equivalent to corn- (stem of cornū) horn + -i- -i- + -culum -cle1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018