/oh"pee euhm/ , n.
1. the dried, condensed juice of a poppy, Papaver somniferum, that has a narcotic, soporific, analgesic, and astringent effect and contains morphine, codeine, papaverine, and other alkaloids used in medicine in their isolated or derived forms: a narcotic substance, poisonous in large doses.
2. anything that causes dullness or inaction or that soothes the mind or emotions.
[ 1350-1400; ME ópion poppy juice, equiv. to op ( ós ) sap, juice + -ion dim. suffix ]