The definition for combustion is "Act of burning." Used in a sentence: Campers must use fire with great caution to prevent combustion of the parched brush.

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 rehash is "To discuss again." Used in a sentence: "Sandra," said her mother, "I am tired of rehashing this same topic over and over."

The definition for solace is "Source of consolation." Used in a sentence: Parents' weekend was a solace to Marjorie, whose beloved daughter had left for college.

The definition for stifle is "To repress or discourage." Used in a sentence: Amy tried ineffectively to stifle her giggles after she read Susan's note in class.