1 forming adjectives meaning 'abounding in, characterized by, of the nature of' (envious; glorious; mountainous; poisonous).
2 Chem. denoting a state of lower valence than the corresponding word in -ic (ferrous).
-ously suffix forming adverbs. -ousness suffix forming nouns.
Etymology: from or after AF -ous, OF -eus, f. L -osus
* * *1. a suffix forming adjectives that have the general sense "possessing, full of" a given quality (covetous; glorious; nervous; wondrous); -ous and its variant -ious have often been used to Anglicize Latin adjectives with terminations that cannot be directly adapted into English (atrocious; contiguous; garrulous; obvious; stupendous). As an adjective-forming suffix of neutral value, it regularly Anglicizes Greek and Latin adjectives derived without suffix from nouns and verbs; many such formations are productive combining forms in English, sometimes with a corresponding nominal combining form that has no suffix; cf. -fer, -ferous; -phore, -phorous; -pter, -pterous; -vore, -vorous.2. a suffix forming adjectival correspondents to the names of chemical elements; specialized, in opposition to like adjectives ending in -ic, to mean the lower of two possible valences (stannous chloride, SnCl2, and stannic chloride SnCl4).[ME < AF, OF < L -osus; a doublet of -OSE1]
* * *-ous /-əs/suffix1. Forming adjectives denoting: character, quality or nature, as in marvellous2. An element in its lower valency, as in sulphurous (chem)ORIGIN: L -osus
* * *-ous,suffix added to nouns to form adjectives.1. having _____; having much _____; full of _____: »
Famous = having much fame. Joyous = full of joy.2. characterized by _____: »
Zealous = characterized by zeal.3. having the nature of _____: »
Murderous = having the nature of murder. Idolatrous = having the nature of an idolater.4. of or having to do with _____: »
Monogamous = having to do with monogamy.5. like _____: »
Thunderous = like thunder.6. committing or practicing _____: »
Bigamous = practicing bigamy.7. inclined to _____: »
Blasphemous = inclined to blasphemy.8. Chemistry. indicating the presence in a compound of the designated element in a lower valence than indicated by the suffix -ic. Stannous means containing tin in larger proportions than a corresponding stannic compound.╂[< Old French -os, -us < Latin -ōsus. -ous is often used to represent the Latin adjective ending, -us, as in Latin omnivorus omnivorous, or the Greek adjective ending, -os, as in Greek anōnymos anonymous]
* * *suffix forming adjectives1) characterized by; of the nature of
dangerous | mountainous2) Chemistry denoting an element in a lower valence
ferrous | sulfurous. Compare with -ic•Origin:from Anglo-Norman French, or Old French -eus, from Latin -osus
* * */əs/ adj suffix: full of : having a large amount of
dangerous [=full of danger]
poisonous [=having or containing poison]
mountainous [=having many mountains]: having the quality of
courageous [=having courage]
glamorous [=having glamour]
* * *(in adjectives) having the nature or quality of
mountainousDerived Words: ↑-ously ▪ ↑-ousnessWord Origin:
* * *-ous, suffixrepr. L. -ōs-us (-a, -um), forming adjs., with the sense of ‘abounding in, full of, characterized by, of the nature of’, e.g. cōpi-ōs-us plentiful, copious, dolōr-ōs-us full of sorrow, dolorous, fām-ōs-us famous, gener-ōs-us distinguished by descent, generous, glōri-ōs-us full of glory, glorious, spīn-ōs-us full of thorns, thorny, spinous, visc-ōs-us of the nature of bird-lime, sticky, viscous, etc. Latin stressed long ō passed in OFr. into a closer sound, intermediate between ō and ū, which was variously written o or u, less commonly ou; hence L. adjs. in -ōsus, which either came down in popular use, or were adopted at an early date, had in OF. forms in -os, or -us (-ous), e.g. coveitos, -us, doleros, -us, envios, -us, glorios, -us, religios, -us. In the 13th c. the vowel-sound had changed to (obar) written eu, so that the suffix had now the form -eus (covoiteus, dolereus, envieus, glorieus, etc.); and this still later was written in the masc. -eux (convoiteux, envieux, glorieux, with fem. however in -euse), as still in modern F. In Anglo-Fr. and early ME. the forms were the same as in early OF. (coveitos, -us, envios, -us, glorios, -us), but the vowel was soon identified with OE. long uacu, and like it written after 1300 ou (covetous, envious, glorious), the spelling ever since retained, though the sound has passed through (-uːs, -us, -ʊs) to (-ʌs, -əs). This -ous, having thus become the form of the suffix in all words from Norman Fr., became the established type for all those of later introduction, whether adaptations of Fr. adjs. in -eus, -eux, or L. adjs. in -ōsus (but see -ose1), or new formations on the analogy of these, from Fr., L., or other elements.These new formations are numerous in the Romanic languages. In French they have been formed freely, not only from L. ns. which had no such derivative in ancient L., but also from French words themselves of L. origin, and from mediæval and modern words from divers sources. Many of these new formations have, in earlier or later times, passed (with change of -eux, etc., to -ous) from French into English. Such is the history, for example, of advantageous, adventurous, courageous, dangerous, gelatinous, grievous, gummous, hazardous, hideous, joyous, lecherous, matinous, mountainous, orguillous, pulpous, ravenous, riotous, slanderous. This process has been continued in Eng. itself, where new adjs. in -ous have been formed, not only on Latin, Greek, and Romanic bases, but also on native Eng. words and on some of obscure origin; e.g. blusterous, boisterous, burdenous, feverous, murderous, poisonous, slumberous, thunderous, timous, troublous, wondrous.In some words in late or med.L. the ending -ōsus was added to an adj., or at least a form in -ōsus is found beside the simple adjective, e.g. decōr-us, decorōs-us, dubi-us, dubiōs-us, in It. decoro, decoroso, dubbio, dubbioso. In the Romanic languages a few new forms of this kind appear; e.g. L. pi-us, F. pi-eux (as if from *piōs-us). But in English, this addition of the suffix has been greatly developed, and has become the ordinary mode of anglicizing L. adjs. of many kinds, esp. those in -eus, -ius, -uus, -er, -ris, -āx -āci, -ōx -ōci, -endus, -ulus, -vorus, -ōrus, e.g. aque-ous, igne-ous, extrane-ous, herbace-ous, consci-ous, obvi-ous, vari-ous, ardu-ous, exigu-ous, adulter-ous, aurifer-ous, armiger-ous, alacri-ous, hilari-ous, illustri-ous, capaci-ous, feroci-ous, stupend-ous, garrul-ous, omnivor-ous, sonor-ous.This tendency to represent a L. adj. by an Eng. form in -ous may have been strengthened by the fact that the ‘dictionary-form’ of the L. adj. is the nom. sing. masc., and that this in the majority of adjs. ends in -us, the Eng. pronunciation of which is the same as that of the Eng. word in -ous, so that the latter to the cursory observer appears to be merely an Eng. spelling of the L. It is evident however that igne-ous, for example, answers not only to L. igne-us, but to igne-a, igne-um, etc., and that the -ous is an additional element. And in comparing alacri-ous with alacer, hilari-ous with hilari-s, capaci-ous with capax, capāci-, the suffixal nature of the -ous is manifest.b. In some words, -ous is a corruption of another suffix, e.g. in righteous, wrongous, courteous, gorgeous; in others, as bounteous, a contraction of an earlier suffix has taken place before -ous: see -eous.c. In Chem., adjectives in -ous, formed on the names of elements, indicate acids and other compounds containing a larger proportion of the element in question than those expressed by an adj. in -ic: e.g. chlorous acid, sulphurous acid, cuprous oxide, ferrous salts, etc.: see -ic 1 b.d. Nouns of quality from adjs. in -ous (however derived), are regularly formed in -ousness, as covetousness, consciousness, gorgeousness, righteousness; those from L. -ōsus have sometimes forms in -osity, as curiosity, generosity, porosity, viscosity; but this termination more frequently accompanies adjs. in -ose1.
Useful english dictionary. 2012.