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 inflammatory is "Tending to excite anger." Used in a sentence: Garth's inflammatory remarks at the party made Gwen furious.

The definition for precept is "A general rule of action." Used in a sentence: All the students know Mrs. Brown's strict precept; no talking in class.

The definition for repel is "To resist, reject." Used in a sentence: The soldiers made a massive charge to repel the invaders.

The definition for untenable is "Not able to be defended." Used in a sentence: Rashid made the untenable statement that George Washington was the second president of the United States.