-ous

 
Pronunciation: /əs/

suffix

  • forming adjectives:
  • 1characterized by; of the nature of: dangerous mountainous
  • 2 Chemistry denoting an element in a lower valency: ferrous sulphurousCompare with -ic

Derivatives

-ously

suffix
forming corresponding adverbs.

-ousness

suffix
forming corresponding nouns.

Origin:

from Anglo-Norman French, or Old French -eus, from Latin -osus