The cause of death was H.I.V.-related illness, said his literary agent, Charlotte Sheedy.

Mr. Wilson was born in Middletown, Conn., graduated summa cum laude from Yale University in 1969 and attended the Columbia University Graduate School of Journalism. In the 1970's and 80's he was an editor at Esquire, GQ and other magazines and a frequent contributor to Artforum and Interview. He later worked as director of research for The National Enquirer and was also an editorial consultant for East/ West, a publisher of airline magazines.

"An Incomplete Education" came about when Mr. Wilson and his co-author, Judy Jones, shared an office in Esquire's research department. Perplexed by the elementary inquiries of the magazine's sophisticated writers, Mr. Wilson turned to his office mate and said: "Haven't these people ever been to college? What they don't know could fill a book." And it did. Published by Ballantine Press in 1987, the hardcover edition is still in print and continues to sell more than 100,000 copies a year.

The witty entries include explanations of the Dred Scott decision and Plato's Cave, as well as topographical terms like swale, vale and dale.

In 1988, after learning that he had AIDS, Mr. Wilson devoted much of his time to political activism on behalf of gay causes. In addition to his work with Act Up, he was a member of the visiting committee at the Robert Mapplethorpe Laboratory for Medical Research at Beth Israel/ Deaconess Hospital in Boston.

Mr. Wilson is survived by a sister, Janet Wilson Schmidt of Middletown.