The definition for catastrophic is "Relating to extreme misfortune." Used in a sentence: The effects of the massive hurricane were catastrophic. The definition for untenable is "not able to be defended.", the definition for derivative is "Lacking originality.", and the definition for opportune is "Suitable or convenient."

The definition for avian is "Relating to birds." Used in a sentence: The old man affectionately referred to pigeons as his "avian friends." The definition for egotist is "self–important person.", the definition for revoke is "To cancel by taking back.", and the definition for trove is "Valuable collection."

The definition for insolence is "Boldness or rudeness." Used in a sentence: The boy's insolence to the policeman embarrassed his mother. The definition for gargantuan is "gigantic.", the definition for regale is "To amuse.", and the definition for adversary is "One who opposes or resists."

The definition for manifest is "Obvious." Used in a sentence: James finally made his affection manifest when he handed Jessica a red rose. The definition for combustion is "act of burning.", the definition for pretense is "False intention or purpose.", and the definition for garish is "Offensively bright."

The definition for penurious is "Extrememly stingy." Used in a sentence: Ebenezer Scrooge was most penurious, refusing to give even a penny to charity. The definition for exasperation is "the state of being irritated.", the definition for abate is "Become less in amount or intensity.", and the definition for rail is "To scold in harsh language."