Opisthocœlian, ō-pis-thō-sē′li-an, adj. hollow or concave behind, as a vertebra.—Also Opisthocœ′lous.

Opisthocomous, op-is-thok′ō-mus, adj. having an occipital crest.

Opisthodomos, op-is-thod′ō-mos, n. a rear-chamber or treasury at the back of the cella in some temples. [Gr.]

Opisthodont, ō-pis′thō-dont, adj. having back teeth only.

Opisthogastric, ō-pis-thō-gas′trik, adj. behind the stomach.

Opisthognathous, op-is-thog′nā-thus, adj. having retreating jaws or teeth.

Opisthograph, ō-pis′thō-graf, n. a manuscript or a slab inscribed on the back as well as the front.—adj. Opisthograph′ic, written on both sides.—n. Opisthog′raphy.

Opium, ō′pi-um, n. the narcotic juice of the white poppy.—n. O′pium-eat′er, one who makes a habitual use of opium. [L.,—Gr. opion, dim. from opos, sap.]

Opobalsam, op-ō-bal′sam, n. a resinous juice, balm of Gilead.

Opodeldoc, op-ō-del′dok, n. a solution of soap in alcohol, with camphor and essential oils, soap-liniment. [Fr., perh. from Gr. opos, juice.]