1. 1. Not adept at reading and writing; deficient in the knowledge that can be acquired from books.
   2. Illiterate.
2. Having no lettering: a plain, unlettered T-shirt.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.