noun
insolence
IN-suh-lens/ˈɪnsələns/
Rude or disrespectful behavior or speech.
The woman's insolence shows as she sticks out her tongue and waves the man away.

Etymology
The pieces originally express being “not accustomed” or unusual. Latin extended this to excess and immoderation, then haughtiness and arrogance—the bridge to disrespectful boldness.
In context
because a slow response could be read as insolence, and insolence could end in dismissal.
More examples
- She apologizes for the insolence of her reply.
- He mistakes her honest question for insolence.
- Rolling your eyes at the judge is sheer insolence.
Forms
insolent adjective — Rude and openly lacking respect.
Similar words
- rudeness
- Covers bad manners generally, without necessarily suggesting defiant disrespect.
- impudence
- Emphasizes shameless boldness in speaking or acting disrespectfully.