not wise in the ways of the world
"either too unsophisticated or too honest to promise more than he could deliver"
"this helplessly unworldly woman"
lacking complexity
"small and uncomplicated cars for those really interested in motoring"
"an unsophisticated machine"
awkwardly simple and provincial
"bumpkinly country boys"
"rustic farmers"
"a hick town"
"the nightlife of Montmartre awed the unsophisticated tourists"
Not sophisticated; lacking sophistication.