Words of the Day are compiled by Isaac Sukin. Chosen words are intended to be useful in written and conversational English. Definitions are sometimes adapted from a variety of sources, including but not limited to Dictionary.com, The American Heritage Dictionary, The Oxford English Dictionary, and Random House Webster's College Dictionary. In general, only primary definitions are used. Occasionally, different forms of a word are not defined, for example if a word can be both a noun and a verb. Semicolons are usually used to separate related definitions.
The Word of the Day is chosen randomly from words and definitions compiled in a database. Words will not be repeated unless every other word in the database has already been used. Words change automatically, but not technically every day: the first time a word appears, a timer is set for 24 hours. The first time after those 24 hours the Word of the Day is viewed, it changes. This could explain why a word may appear to be used two days in a row.