スマート辞書は無料で、メリアム・ウェブスターのカレッジ英英辞典に基づいています
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.)