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 brandish is "To shake or wave menacingly." Used in a sentence: The baseball player was fined for brandishing his bat at the opposing pitcher.

The definition for commemorate is "To mark by a ceremony." Used in a sentence: Each year, the Franklins commemorate their anniversary by visiting the site of their first date.

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 polarize is "To break up into opposing groups." Used in a sentence: Thelma tended to polarize discussions rather than to encourage compromise.