American Heritage Thesaurus 4+

English Dictionary & Thesaurus

MobiSystems, Inc.

Designed for iPad

    • 4.1 • 193 Ratings
    • $19.99



Enjoy an advanced Dictionary & Thesaurus bundle from one of the US’ most trusted language sources, The American Heritage, directly on your device.

The application is regarded as one of the flagship products in Houghton Mifflin Harcourt catalog, featuring advanced search and learning tools designed by a vastly experienced developer. It combines rich Dictionary database and extensive Thesaurus vocabulary.

- THE AMERICAN HERITAGE® DICTIONARY OF THE ENGLISH LANGUAGE contains 10,000 new words and phrases, over 4,000 dazzling new full-color images, and authoritative, up-to-date guidance on usage. Thousands of definitions have been revised in rapidly changing fields such as astronomy and biology. Geographical entries and maps have been completely updated, and the dictionary’s signature feature notes on word history, synonymy, and language variation have all been enhanced and improved.

- THE AMERICAN HERITAGE® ROGET'S THESAURUS offers an intelligent and sensible guide to synonym selection. It provides a wide range of synonyms, ranging from mainstream vocabulary to the colorful alternatives that make English such a rich and versatile language. Thousands of slang, informal, and regional words broaden the coverage even further. Each synonym list focuses on a clear definition that quickly guides the user to the relevant meaning.

This app is tailored to professionals, students, and academics, as well as anyone who needs a comprehensive and authoritative dictionary of current English at work or at home.

 • Learn in style with any of the four colorful new themes – The colorful layout will turn your learning experience into an enjoyable routine. Customize your dictionary and benefit from the cheerful mood your favorite color brings you.
 • Dive right into the intricacies of the language - With new and convenient Home page, sleeker and more intuitive visual layout, as well as innovations that enhance the speed of searches, you can get to the desired entry faster than ever.
 • Translate and learn as you speak by using Talk & Translate – Use the speech recognition & text-to-speech app by downloading it for Free from the App Store. The great synergy between the two apps will be there to help you optimize your studies.

SEARCH TOOLS - quickly find words with the clear, functional, and easy-to-use interface.
Designed to provide the most comprehensive search experience, the dictionary combines several search tools to match or predict what are you looking for, including:
 • Search autocomplete - helps you find words quickly by displaying predictions as you type.
 • Keyword lookup - allows you to search within compound words and phrases.
 • Camera search looks up words in the camera viewfinder and displays results in seconds.
 • Voice search - helps you find an entry when you don’t know how a word is spelled.

Looking for a specific word but don't know how it's spelled? We've got you covered with our automatic ‘Fuzzy filter’ to correct word spelling, as well as ‘Wild card’ filter to replace a letter or entire parts of a word with '*' or '?'.

LEARNING TOOLS - engaging features that help you further enhance your vocabulary. Designed to give you freedom to structure your studies, the dictionary combines several learning tools to help you be more organized, including:
 • ‘Favorites’ that allow you to create custom folders with lists of words.
 • Recent list which helps you to easily review looked-up words.
 • Swipe-to-delete functionality in the Recent and Favorites menus.
 • Word-of-the-day option to teach you a new word every day.

Feel excited by the new word or definition you just learned? Share your discovery with friends on social media, email or any other option available on your device.

What’s New

Version 10.0.11

This app has been updated by Apple to display the Apple Watch app icon.

•New vocabulary database (2018 edition).
•Four new colorful themes.
•Delete and sort entries with Favorites/Recent list.
•Dictionary & Thesaurus displayed in Word-of-the-Day.

Ratings and Reviews

4.1 out of 5
193 Ratings

193 Ratings

scaredAgency ,


It is certainly useful for those who are simply looking for an American heritage dictionary. As an app, it's features are lacking. For example, an older version (around iOS 5) allowed quizzes with your bookmarks and games. Design wise, there are two different buttons for audio playback? Unless I'm missing something there. Would like to see some more features for a $20 app. Though having the American heritage dictionary in your pocket is great. I haven't experienced any crashes on iOS 9.

Developer Response ,

Thank you for your comment! We are constantly working on improving the application, so please follow our next updates.

ML77&& ,

Intentional app rating scheme is unforgivable

This is about the sixth time I've bought the American Heritage dictionary as a book, a paperback, 30 floppy discs, a book with an app on CD, an iOS app, and now the newer iOS app since the previous version "aged out." Sadly, I bought it a few days after iOS 10 — and it won't run. I hope its fixed soon so I can concentrate on having a high quality, offline, robustly featured dictionary of authority at my fingertips.

Update: The app was updated to run in iOS 10, allowing me to use it and to discover an unforgivable characteristic of the app. Nearly every time I go to use it, a pop up appears over the screen; it gives you two options: rate the app five stars, or choose "not yet." In other words, it presents a situation where you can give the app the highest possible review, or no review at that moment — meaning that you'll be asked this question over and over again. I assume the only way to turn this irritating thing off is to rate the app five stars. It doesn't deserve five stars — for this one "feature" alone, it deserves zero stars. Shame on Houghton Mifflin, the dictionary's publisher, for allowing MobiSystem, Inc. to denigrate their reputable dictionary with such a cheap ploy in a premium-priced app.

Developer Response ,

We are sorry to hear you are disappointed by the app. Please contact our support services at:, so we could help you resolve the issue.

Erik Steinmetz ,

Disappointing Implementation

I love the AH dictionary and have many copies in paper and electronically. This implementation, though it contains all the content, is disappointing from a user interface perspective. The pestering dialog to rate the app (apparently only as five stars) never gives up even after you have declined to do so many times over years of use. The limited choice of color themes (only four) are all too bright, disallowing any subdued choices. The navigation design is especially poor in the special portions such as trying to browse the appendices or looking through the index of tables: the upper-left back button alternatively brings you back to the location from which you arrived (correct) or simply the item listed immediately before the one you’re currently looking at (incorrect). I hope that this developer can start paying attention to details, or that AH passes its app along to someone else (for which I would happily pay again given this app’s shortcomings)

App Privacy

The developer, MobiSystems, Inc., has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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