We all know what the words cat and dog and mother and tree mean. What we really need is a dictionary that helps us with the tough words, like elucubrate, or demesne, or cynosure. True, a standard dictionary can bail us out when we run across a tough word at home or in a library. But we often read elsewhere--in a doctor's waiting room or on a plane, or while on vacation. What do we do then?

The Oxford Dictionary of Difficult Words is designed to meet this need. A portable reference, it features more than 10,000 entries...