late Old English wæsc "act of washing," from wash (v.). Meaning "clothes set aside to be washed" is attested from 1789; meaning "thin coat of paint" is recorded from 1690s; sense of "land alternately covered and exposed by the sea" is recorded from mid-15c.
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy).