Diction

Improve your diction (choice of words, style of writing or speaking) with the help of a thesaurus or dictionary:

Cambridge Dictionary for English Learners with understandable and straightforward definitions

yourdictionary.com definitions from several different dictionaries all on the same page, and examples of the word used in sentences 

Merriam Webster includes examples sentences and examples of the word used in context from literature and around the web

thesaurus.yourdictionary.com  improve your writing with descriptive words--instead of "walk" you could use "march," "ramble," "tread," or "tramp."