An abnormal triangular growth of fibrovascular tissue beneath the bulbar conjunctiva of the eye, typically having its base at the medial canthus and its apex towards or into the cornea, and often associated with excessive exposure to ultraviolet light.

An abnormal condition of the nail in which the cuticle extends forward over the nail plate. More fully "pterygium unguis".

An abnormal web of skin, especially situated on the neck (more fully "pterygium colli") or in the antecubital, popliteal, or interdigital regions.