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.

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.

The definition for incisive is "Impressively direct and decisive." Used in a sentence: Samir's incisive leadership made him the natural choice for president of the company.

The definition for pallid is "Lacking color." Used in a sentence: The nurse was worried by the patient's pallid face and shallow breathing.

The definition for polarize is "To break up into opposing groups." Used in a sentence: Thelma tended to polarize discussions rather than to encourage compromise.