fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
indecorous
The definition for indecorous is "In bad taste." Used in a sentence: My parents banned Chad from our house because of his indecorous behavior at dinner.
lenient
The definition for lenient is "Mild or tolerant." Used in a sentence: The judge issued a lenient sentence because it was Frank's first offense.
polarize
The definition for polarize is "To break up into opposing groups." Used in a sentence: Thelma tended to polarize discussions rather than to encourage compromise.
revive
The definition for revive is "To bring back to life." Used in a sentence: Hank tried to revive Clare's interest in the project, but her enthusiasm had expired.