1859, "dirty, stained, or blackened," from smudge (n.) + -y (2). The meaning "blurry, indistinct" is by 1865. Related: Smudginess.
Entries linking to smudgy
smudge v.
early 15c., smogen "to soil, smear or stain with dirt or filth, blacken," a word of obscure origin. Compare smutch and its variant smouch, Middle English smod "filth, obscene behavior" (mid-13c., also a surname); Middle Dutch besmodden, smoddich, Middle Low German smudden.
The meaning "to rub out or in" is by 1865. Related: Smudged; smudging. The noun meaning "a dirty mark or stain, spot, smear" is attested by 1768, from the verb.
The smudge meaning "make a smoky fire" is by 1860, also of unknown origin, but perhaps related. According to OED now dialectal and North American. OED also gives it in an earlier, obsolete sense of "cure (herring, etc.) by smoking" (1590s).
The related noun smudge is attested by 1767 as "a suffocating smoke" (to repel mosquitoes, etc.); from 1806 as "heap of combustibles ignited and emitting dense smoke." Hence smudge-pot (1903). Smudge-stick as a Native American (Crow tribe) artifact is by 1908
-y 2
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). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.