Definition of plica in US English:



  • 1Anatomy
    A fold or ridge of tissue.

    • ‘These commarginal lirae broadly tongue dorsally across plicae and ventrally across interspaces.’
    • ‘Commissure crenulated at intersection with plicae and nodes posteriorly.’
    • ‘The plesiomorphic condition in both adults and larvae of the lorica seems to be a thin lorica with many plicae.’
    • ‘The alar plica or alar folds are prominent crescentic folds of synovial membrane, extending dorsalward on each side of the patella from the base of the infrapatellar synovial fold.’
    • ‘Fibrosis of the tubal plicae was noticed in 35.5% of the specimens and was graded as mild, moderate, or severe.’
    1. 1.1Botany A small lobe between the petals of a flower.
      • ‘Loxochlamys having 13-15 prominent radial rounded-trigonal plicae that begin early in ontogeny and remain of moderate height throughout ontogeny.’
      • ‘In addition the plicae/petal size relationship was of the Gentians sap onaria type.’
      • ‘The Plica Triangularis extended into the right frontal lobe.’
  • 2Medicine
    A densely matted condition of the hair.

    • ‘Diseased hairshafts are likely to be more susceptible to Plica polonica.’
    • ‘It has been suggested that Plica Polonica may be associated with damage to sections of the cuticle.’


Mid 17th century: modern Latin, from medieval Latin, ‘fold’, from plicare ‘to fold’.