The definition for periodic is "Occurring at regular intervals." Used in a sentence: The periodic innterruptions of the cuckoo clock prevented Li from concentrating. The definition for lenient is "mild or tolerant.", the definition for foil is "One that enhances or underscores by contrast.", and the definition for augment is "To make greater."

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. The definition for combative is "eager to fight.", the definition for flaunt is "To display showily.", and the definition for prudent is "Marked by wisdom, shrewd."

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 exception is "a case to which the rule does not apply.", the definition for catastrophic is "Relating to extreme misfortune.", and the definition for derivative is "Lacking originality."

The definition for discern is "To recognize as separate as distinct." Used in a sentence: The pastry connoisseur was able to discern Swiss from Belgian chocolate. The definition for lenient is "mild or tolerant.", the definition for deferment is "The act of delaying.", and the definition for recrimination is "A retaliatory accusation."

The definition for negate is "To make invalid." Used in a sentence: Paula negated Tiffany's argument by proving that her main premise was false. The definition for inflammatory is "tending to excite anger.", the definition for solace is "Source of consolation.", and the definition for exalt is "To elevate by praise."