aerate
The definition for aerate is "To supply with air." Used in a sentence: Every spring, Soloman used his tiller to aerate the compact soil.
commemorate
The definition for commemorate is "To mark by a ceremony." Used in a sentence: Each year, the Franklins commemorate their anniversary by visiting the site of their first date.
flagrant
The definition for flagrant is "Noticeably offensive." Used in a sentence: The executive was fired for his flagrant abuse of the company expense account.
gravity
The definition for gravity is "Importance, significance." Used in a sentence: Understanding the gravity of his error, Ken offered his humblest apology.
unscrupulous
The definition for unscrupulous is "Lacking principles." Used in a sentence: The unscrupulous salesman was fired for lying to his customers.