If you're a working adult who's neither in school nor a writer, you probably haven't heard the word "thesaurus" in quite a while. But even if you only write or communicate minimally in your job, a thesaurus can help you expand your traditional vocabulary and exercise your brain.

Rather than learning an entirely new word every day with a dictionary app, you can learn a synonym or antonym for a word you're already familiar with instead. Think about a word you often use, and see if there are any catchy alternatives in one of these thesaurus apps for Android and iPhone that could spice up your vocab.

1. Power Thesaurus

There are no frills with the Power Thesaurus app. The home screen is an almost entirely blue screen with a single search bar at the top. Look up the word you want alternatives for, and an extensive list will populate in seconds.

After you search for a word, you'll see an estimate of how many synonyms exist within the app for that word, as well as the most popular synonyms below the search bar. In addition to synonyms, there are other tabs you can swap between, each of which similarly displays the number of entries in that tab and the most popular ones front and center.

These tabs include Antonyms, Definitions, Sentences, Related, Broader, Narrower, Similar, Sound Like, and Rhymes. You can reorder these tabs if you find you're using some more than others. Being able to search for synonyms and find similar words that are narrower or broader is a very helpful tool for students and writers.

Download: Power Thesaurus for Android | iOS (Free)

2. Concise Oxford Thesaurus

Oxford is a huge name in the world of informational books. In both the Apple Store and the Google Play Store, there are countless Oxford dictionary apps in different languages along with other helpful apps for wordsmiths.

When you first download the Concise Oxford Thesaurus, the app automatically starts a 30-day free trial, and at the end of the trial, you have to pay a one-time fee of $7.49 to keep it.

When searching for a word, you'll see different contexts the word might be used in as well as synonyms for each one. For example, if you search "tired," you'll see three use cases listed: "you're just tired from traveling," "are you tired of having him here?", and "tired jokes." Each use case has unique synonyms listed beside it.

While Android users have access to Oxford's Concise Thesaurus, iOS users can download a combined Advanced Dictionary & Thesaurus from the same developers. With either app, you'll expand your vocabulary and impress your friends.

Download: Concise Oxford Thesaurus for Android (Free, in-app purchases available)

Download: Advanced Dictionary & Thesaurus for iOS (Free, in-app purchases available)

3. Word Hippo

Word Hippo has such a delightful user interface, and the home screen always displays a new word every day with its contexts, synonyms, and related words listed below. You can tap on any of the synonyms to open up a new page and see all contexts for that word as well.

If you want to look up antonyms, you'll have to switch over to the Opposite Words tab in the side menu. Tapping on the three horizontal lines in the top left corner opens this menu, and you can also look at Definitions, Translations, Sentences, Rhymes, and Word Forms.

The only in-app purchase is for $1.99 to remove ads and save words to your bookmarks within the app.

Download: Word Hippo for Android | iOS (Free, in-app purchases available)

4. Pocket Thesaurus

On the home screen of Pocket Thesaurus, there's an overview of all the useful features you can find within the app. There's a Search function, of course, that lets you type any word you can think of into the search bar at the top and see all similar and opposite words in a neatly organized paragraph.

Then, you can use the Bookmark feature by tapping the star next to any word that you search for, and you can view all your starred words whenever you want. If you can't remember what word you searched previously, use the History function to pull up past words you've looked up along with the specific date and time of your search.

If you love playing word games like crosswords or scrabble games, you can use the Advanced/Crossword Search feature to help you find the best word. Using the question mark symbol and the star symbol on your keyboard, you can perform a selective search to replace single letters or multiple successive letters.

Pocket Thesaurus is one of the few thesaurus apps out there that lets you generate an overlay on top of other apps, meaning you don't have to copy a word from one app and then paste it into the Pocket Thesaurus app. Instead, you can copy a word anywhere on your device and see its synonyms in a popup window. All you have to do is enable Floating Thesaurus in the app's settings.

There's a monthly subscription fee of $0.99 for Pocket Thesaurus Premium, but this recurring fee only removes ads.

Download: Pocket Thesaurus for Android | iOS (Free, subscription available)

5. Collocations Thesaurus Offline

The Collocations Thesaurus app is awesome if you don't always know which words you want to look up, but just know you want to learn new synonyms for common words. There's also a dictionary feature within this app, but you can easily swap over to the thesaurus feature with the side menu. From there, you'll see a list of top words to browse through and view all the best synonyms for each one.

Many thesaurus apps show every possible synonym for a word, but if you're not careful, you could end up writing something that sounds super confusing. The Collocations Thesaurus app shows you a few of the best possible synonyms instead, often somewhere in the range of four to seven similar words.

This app is only available on Android devices and there's not a great alternative for iOS devices, but all the other thesaurus apps on this list are great for both Android and iOS users. The only in-app purchase is to remove ads for a one-time fee of $2.99.

Download: Collocations Thesaurus Offline for Android (Free, in-app purchases available)

Have a Thesaurus at the Ready Wherever You Go

With smartphones, it's possible to take loads of helpful tools and books along with you on any outing. Why not add a thesaurus to that mix?

When you're home and have access to your computer, using a thesaurus site or one built into Google Docs might be your go-to option. But when you're out and about, you can always depend on your mobile thesaurus app and find the perfect word.