Definition of -ous in English:

-ous

suffix

  • 1Forming adjectives:

    1. 1.1 Characterized by; of the nature of.
      ‘dangerous’
      ‘mountainous’
    2. 1.2Chemistry Denoting an element in a lower valence.
      ‘ferrous’
      Compare with -ic
      ‘sulfurous’

Origin

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

Pronunciation:

-ous

/əs/