/sawr"euh leuhn, sohr"-/ , n. Pharm.
a toxic substance, C 11 H 6 O 3 , found in certain plants, including parsnips, used to increase the response to ultraviolet light in the treatment of severe cases of acne and psoriasis.
Also called furocoumarin .
[ 1930-35; Psoral ( ea ) name of a genus of plants yielding the compound ( psoraléa, neut. pl. of PSORALÉOS mangy, in reference to the glandular dots on the plant; see PSORIASIS) + - en, var. of -ENE ]