Smart Dictionary

Smart Dictionary is a free dictionary based on Merriam-Webster's Collegiate Dictionary.

In addition, this app offers voice search - to let you look up a word without having to spell it - along with synonyms, antonyms, example sentences, and more.

It's a great tool for reference, education, and vocabulary building.

The app is free, no ads.

No internet connection is required to view the definitions or thesaurus(although you do need a connection to hear audio pronunciations and use voice search.)