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 benefactor is "one who offers financial help.", the definition for revoke is "To cancel by taking back.", and the definition for colossal is "Immense, enormous."

The definition for fragile is "Delicate." Used in a sentence: Jade placed the fragile vase out of reach of her rambunctious boys. The definition for heed is "to pay attention to.", the definition for entangle is "To involve in trouble.", and the definition for ethical is "Conforming to accepted standards."

The definition for extant is "Currently existing." Used in a sentence: Some consider Clint Eastwood the greatest extant American director. The definition for corroborate is "to support with evidence.", the definition for heinous is "Shockingly evil.", and the definition for buffer is "Protective barrier."

The definition for ploy is "A contrived plan." Used in a sentence: Sarah thought George's ploy of borrowing her notes was a cowardly way to ask her out. The definition for obnoxious is "highly offensive.", the definition for euphoria is "Feeling of great happiness.", and the definition for incongruous is "Not harmonious, incompatible."

The definition for raucous is "Noisy, rowdy." Used in a sentence: Serena, who preferred quiet conversation, left the rancous party. The definition for stealth is "the act of moving secretly or unnoticed.", the definition for apathetic is "Showing little or no emotion.", and the definition for preclude is "To rule out in advance."