Look at issue #18 of The Perl Journal, Volume 5, Number 2 (#18), Summer 2000. It has an article on Lingua::Wordnet, which can do what you want (actually, it can do much more) by searching the Wordnet database.

WordNet® is an on-line lexical reference system whose design is inspired by current psycholinguistic theories of human lexical memory. English nouns, verbs, adjectives and adverbs are organized into synonym sets, each representing one underlying lexical concept. Different relations link the synonym sets. WordNet was developed by the Cognitive Science Laboratory at Princeton University under the direction of Professor George A. Miller (Principal Investigator).

As a demo, this is the Wordnet output on a query of "Pearl" (no, it won't find Perl).

BTW, this Wordnet stuff is a real gem - it comprises many, many years of expert linguist's work, and it's free, too: "WordNet® is unencumbered, and may be used in commercial applications in accordance with the following license agreement. An attorney representing the commercial interest should review this WordNet license with respect to the intended use. ( ... snip ... ) Permission to use, copy, modify and distribute this software and database and its documentation for any purpose and without fee or royalty is hereby granted, (... snip ...)"

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com