psoralen: Meaning and Definition of

pso•ra•len

Pronunciation: (sôr'u-lun, sōr'-), [key]
— n. Pharm.
  1. a toxic substance, CHO, found in certain plants, including parsnips, used to increase the response to ultraviolet light in the treatment of severe cases of acne and psoriasis.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.