any of various derivatives of coumarin used in drugs to treat psoriasis, etc.: when activated by sunlight it causes the skin to darken
Any of a group of chemical compounds found in certain plants, used to treat psoriasis and vitiligo.
Origin of psoralenFrom New Latin Psōralea, plant genus, from Greek psōralea, neuter pl. of psōraleos, mangy (from the appearance of the plants' leaves), from psōrā, itch.