Formal:
* He had the effrontery to question the CEO's decision in front of the entire board.
* The defendant's effrontery in claiming innocence, despite overwhelming evidence, was shocking to everyone in the courtroom.
Informal:
* It takes effrontery to walk into a party uninvited and start making yourself at home.
* I couldn't believe her effrontery in asking me to pay for her coffee after she spilled hers all over me.
Figurative:
* The invading army had the effrontery to claim they were liberating the people, while their actions clearly showed their true intentions.
Key points:
* Effrontery implies audacity, boldness, and a disregard for propriety.
* It's often used in a negative context, highlighting someone's disrespectful or impudent behavior.
* You can use it to describe someone's actions or their attitude.