Used in chemical nomenclature to name chemical compounds in which a specified chemical element has a lower oxidation number than in the equivalent compound whose name ends in the suffix -ic. For example sulphuric acid (H2SO4) has more oxygen atoms per molecule than sulphurous acid (H2SO3). See Inorganic nomenclature
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
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