beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
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.
ethical
The definition for ethical is "Conforming to accepted standards." Used in a sentence: Mary did the ethical thing and turned in the diamond necklace she found.
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.
foil
The definition for foil is "One that enhances or underscores by contrast." Used in a sentence: The sweet cookie was a perfect foil to the sour lemon sorbet.