from The American Heritage® Dictionary of the English Language, 4th Edition
- suffix Having; having the qualities of; full of: bilious.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- suffix Alternative spelling of -ous.
Middle English, partly from Latin -ius and partly from Old French -ieus, -ieux (from Latin -iōsus).(American Heritage® Dictionary of the English Language, Fourth Edition)
-i- + -ous (Wiktionary)