-ious

Suffix

-ous

1. possession of
   • bulb + -ous → bulbous

   Synonyms:

   -ate

2. presence of a quality in any degree (typically an abundance)
   • courage + -ous → courageous
3. relation or pertinence to
   • aptonym + -ous → aptonymous
4. 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.

   Synonyms:

   -y