elusive
The definition for elusive is "Hard to grasp." Used in a sentence: The words to the song are elusive, as the singer tends to mumble.
euphoria
The definition for euphoria is "Feeling of great happiness." Used in a sentence: Cassandra was overcome with euphoria when she met her long–lost sister.
fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
moderate
The definition for moderate is "Tending toward the average." Used in a sentence: The best–selling writer was disappointed; his new novel was only a moderate success.
perception
The definition for perception is "Capacity for seeing or understanding." Used in a sentence: His incredible perception made him the best detective on the force.