avian
The definition for avian is "Relating to birds." Used in a sentence: The old man affectionately referred to pigeons as his "avian friends."
catastrophic
The definition for catastrophic is "Relating to extreme misfortune." Used in a sentence: The effects of the massive hurricane were catastrophic.
ecstatic
The definition for ecstatic is "Overwhelmingly emotional." Used in a sentence: They were ecstatic when their team won the championship game in the last second.
retroactive
The definition for retroactive is "effective as of a prior time or condition." Used in a sentence: The retroactive law made even past infractions punishable.
scamper
The definition for scamper is "To run quickly." Used in a sentence: The frightened kitten scampered away from the butterfly.