from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An abnormal mass of tissue arising from the conjunctiva of the inner corner of the eye that obstructs vision by growing over the cornea.

from The Century Dictionary.

  • noun In zoology and anatomy, a limb or member of one of the vertebrates, as a fish, in the most general sense, without reference to its specialization in any given instance.
  • noun In pathology, a more or less triangular patch of hypertrophied conjunctiva and subconjunctival tissue with its apex at the edge of the cornea or upon the cornea.
  • noun In entomology, one of the two lateral expansions at the end of the rostrum of certain weevils. They lie above and partly conceal the scrobes or grooves in which the antennæ are concealed.
  • noun An instrument employed in the operation for the removal of a pterygium from the cornea.
  • noun A forward growth of the eponychium over the nail-plate.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Med.) A superficial growth of vascular tissue radiating in a fanlike manner from the cornea over the surface of the eye.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun medicine An abnormal mass of tissue in the corner of the eye that obstructs vision

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun either of two thickened triangular layers of conjunctiva extending from the nasal edge of the eye to the cornea; it arises from irritation of the pinguecula


from The American Heritage® Dictionary of the English Language, 4th Edition

[New Latin, from Greek pterugion, diminutive of pterux, pterug-, wing; see pterygoid.]


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  • In anatomy:

    a. A diseased condition of the conjunctiva of the eye

    b. A growth of the epidermis over the nails

    In botany:

    Term applied to petals and other appendages when shaped like wings

    February 3, 2007