From The Collaborative International Dictionary of English v.0.48 :
bumpkinly \bump"kin*ly\ adj.
unsophisticated in a manner resembling a lifelong resident of
rural areas; as, bumpkinly country boys.
Syn: hick, rustic, unsophisticated.
[WordNet 1.5 +PJC]
From WordNet (r) 3.0 (2006) :
bumpkinly
adj 1: awkwardly simple and provincial; "bumpkinly country
boys"; "rustic farmers"; "a hick town"; "the nightlife of
Montmartre awed the unsophisticated tourists" [syn:
bumpkinly, hick, rustic, unsophisticated]