var. of -ous: gaseous
Origin of -eousfrom Classical Latin -eus + -ous
Having the nature of; resembling: gaseous.
Origin of -eousMiddle English from Old French -eux, -eus ( from Latin -ōsus ) and from Latin -eus
From earlier -uous, alteration of -wose, -wos, a variant of -wise, from Middle English -wise, -wis, -wys, from Old English -wīs (“-wise”). More at -wise.