treˈtinəwə̇n noun
( -s )
Etymology: perhaps from t rans- + retino ic acid (herein) + -in
: the all-trans isomer of retinoic acid that is applied topically to the skin to treat acne vulgaris and to reduce facial wrinkles, roughness, and pigmented spots and that is administered orally to induce remission of acute myelogenous leukemia in which more than half the cells are malignant premyelocytes