Onst, wunst, adv. a vulgar form of once.
Onstead, on′sted, n. (Scot.) a farmstead, the farm buildings. [M. E. wone—A.S. wunian, to dwell, stead, place.]
Ontogenesis, on-tō-jen′e-sis, n. the history of the individual development of an organised being as distinguished from phylogenesis and biogenesis—also Ontog′eny.—adjs. Ontogenet′ic, -al, Ontogen′ic.—adv. Ontogenet′ically. [Gr. onta, things being, neut. pl. of ōn, pr.p. of einai, to be, genesis, generation.]
Ontology, on-tol′o-ji, n. the science that treats of the principles of pure being: that part of metaphysics which treats of the nature and essence of things.—adjs. Ontolog′ic, -al.—adv. Ontolog′ically.—n. Ontol′ogist, one versed in ontology. [Gr. ōn, ontos, being pr.p. of einai, to be, logia—legein, to discourse.]
Onus, ō′nus, n. burden: responsibility.—Onus probandī, the burden of proving. [L. onus, burden.]
Onward, on′ward, adj. going on: advancing: advanced.—adv. (also On′wards) toward a point on or in front: forward.
Onym, on′im, n. (zool.) the technical name of a species or other group.—adjs. On′ymal, Onymat′ic.—v.i. On′ymise.—n. On′ymy, the use of onyms.
Onyx, on′iks, n. (min.) an agate formed of layers of chalcedony of different colours, used for making cameos.—ns. Onych′ia, suppurative inflammation near the finger-nail; Onychī′tis, inflammation of the soft parts about the nail; Onych′ium, a little claw; On′ychomancy, divination by means of the finger-nails; Onychonō′sos, disease of the nails.—adj. Onychopath′ic, affected with such.—n. Onychō′sis, disease of the nails. [L.,—Gr. onyx, onychos, a finger-nail.]
Oodles, ōō′dlz, n. (U.S.) abundance.—Also Ood′lins.
Oof, ōōf, n. (slang) money.