"full of entanglements or imperfections," 1864, from nub + -y (2). Nubbly, "having numerous knobs or lumps," is from 1814.
Entries linking to nubby
nub n.
"knob, lump, bump, protuberance," 1590s, variant of dialectal knub, which is probably a variant of knob. Figurative meaning "point, gist" is attested by 1834.
-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.