Wiktionary
a. insufficient educated.
WordNet
adj. poorly or insufficiently educated
Usage examples of "undereducated".
But what they really are is a bunch of poor, undereducated white trash making a subsistence living up here in the hills.
Some of our members had come from very poor, undereducated backgrounds, and we were not properly trained in social reeducation.
American is as undereducated and stupid as the average british subject.
The Open Conspiracy proposes to end and shows how an end may be put to that huge substratum of underdeveloped, undereducated, subjugated, exploited, and frustrated lives upon which such civilization as the world has known hitherto has rested, and upon which most of our social systems still rest.
I don't know whether the people in these towns pronounce them that way because they are backward, undereducated shitkickers who don't know any better or whether they know better but don't care that everybody thinks they are backward undereducated shitkickers.