Let’s do another word count (see “Sadness” for our first one): variations of “phony” occur 47 times in Catcher in the Rye. That’s a lot. Trust us. Phoniness is—well, everything from pretense to social snobbery to language to appearances. You could say that it’s anything Holden doesn’t like. You could also say that it’s anything that makes people less childlike and less innocent. You could also say that the whole foundation of civilization and society is based on what Holden calls “phoniness,” so … he should probably either learn to deal with it, or go ahead and run off to that cabin in the woods already.
Although Holden appears to judge only adults as "phonies," there’s nothing specifically keeping kids from being phony, too.
Holden is possibly the biggest phony we meet in Catcher in the Rye.