-ous

-ous. Etym: [OF. -ous, us, -os, F. -eux, fr. L. -osus, and -us. Cf. - ose.] 1. An adjective suffix meaning full of, abounding in, having, possessing the qualities of, like; as in gracious, abounding in grace; arduous, full of ardor; bulbous, having bulbs, bulblike; riotous, poisonous, piteous, joyous, etc. 2. (Chem.) Defn: A suffix denoting that the element indicated by the name bearing it, has a valence lower than that denoted by the termination -ic; as, nitrous, sulphurous, etc., as contrasted with nitric, sulphuric, etc.

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