-ous

American  

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;

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, SnCl 2 , and stannic chloride SnCl4 ).

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-ous British  

suffix

1. having, full of, or characterized by

   dangerous

   spacious

   languorous

2. (in chemistry) indicating that an element is chemically combined in the lower of two possible valency states Compare -ic

   ferrous

   stannous

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Etymology

Origin of -ous

Middle English < Anglo-French, Old French < Latin -ōsus; a doublet of -ose ¹

Example Sentences

Some words ending in -ous are not of this class.

From Society for Pure English Tract 4 The Pronunciation of English Words Derived from the Latin by Sargeaunt, John

Biramose -ous: having two branches or doubled appendages.

From Explanation of Terms Used in Entomology by Smith, John. B.

Rugose -ous: wrinkled: with irregular waved elevated lines.

From Explanation of Terms Used in Entomology by Smith, John. B.

Monotrocha -ous: Hymenoptera in which the trochanters are single: having legs in which the trochanter is one-jointed.

From Explanation of Terms Used in Entomology by Smith, John. B.

If more than two be known, the one inferior in oxygen content has the prefix hypo- and the termination -ous, and the one superior in oxygen content has the prefix per- and the termination -ic.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" by Various