əs adjective suffix
Etymology: Middle English, partly from Old French -ous, -os, -eus, -eux, from Latin -osus; partly from Latin -us (final portion of the nominative singular masculine form of adjectives such as fatuus foolish, fuscus brown
1. : full of : abounding in : having : possessing the qualities of
clamor ous
glamour ous
cyst ous
lymph ous
2. : having a valence lower than in compounds or ions named with an adjective ending in -ic
ferr ous iron
sulfur ous acid
— compare -ite II
• -ous·ly