A dictionary which omits obscure words. Abridge means to shorten, or skip or leave out stuff, and so it implies that it is a shortened version of a more complete dictionary, called an unabridged dictionary.

Merriam-Webster's Collegiate Dictionary, Tenth Edition is an example of an abridged dictionary. Merriam-Webster's New International Dictionary, Second Edition is an example of an unabridged dictionary.

A mostly useless thing for the most part, omiting most of the words one might need a dictionary for, but including all the one-syllable words containing fewer than nine letters your average person might have learned in grade school. The Highly Selective Dictionary for the Extraordinarily Literate is a kind of anti-abridged dictionary.