As with the other dictionaries reviewed here, the Concise English Dictionary skimps on pronunciation and etymology. On the whole, however, the app's clean interface, speed, size and make it a compelling and useful addition to the iPhone or iPod touch.

None of the aforementioned apps, however, quite compare to TanCreative Software's WordBook. The developer boasts that it is the "most downloaded commercial English dictionary" in the App Store. It's not hard to see why. Wordbook's interface is clean and professional, with customizable text size. When you examine an entry, you can finger drag the page to reveal more options, including a favorites button, multiple Web links, and the app's thesaurus.

When you launch WordBook, you get the words of the day. Note that it's words, not word. Touch a word, get a definition. ("Wassail," a noun, is a punch made of sweetened ale or wine heated with spices and roasted apples; especially at Christmas.) Shake the device, get more words. WordBook handles partial matches and wildcard searches with ease. And WordBook's browser has a feature I hadn't seen before: A three-tier A-Z scroll. You can tap on the first, second and third letters of a word or word family and WordBook will jump instantly to that section.

WordBook doesn't have quite as many entries as the Concise English Dictionary--150,000 entries versus 250,000--but WordBook is more thorough. Each entry includes the part of speech, a short definition, hyperlinked synonyms and, yes, pronunciation. Some entries even have etymology. And in cases where the short definition isn't sufficient--as with certain proper names or concepts--you can tap the "web" button behind the main entry screen. If you have a Wi-Fi connection, WordBook will launch Wikipedia or Google Answers within the app and expound on the word. As a bonus for puzzle and Scrabble lovers, WordBook has a nifty crossword finder and anagram maker. As dictionaries go, WordBook offers very good resource at a great value.

That said, none of these dictionaries is as good as Webster's New College Dictionary, let alone the unabridged Third International or the OED. You really do get what you pay for, as we'll see when I review those three offerings.