Formal:
* Insolent: This is a good synonym that implies disrespect and arrogance.
* Presumptuous: This suggests someone acting with unwarranted boldness or confidence.
* Audacious: This emphasizes boldness and a disregard for consequences.
Informal:
* Cheeky: This is a less formal and more playful synonym, often used to describe someone who is playfully disrespectful.
* Sassy: This implies a confident and somewhat defiant attitude.
* Brash: This suggests someone is bold and perhaps a little rude.
Other options:
* Rude: This is a general term for being disrespectful.
* Disrespectful: This is a more formal and neutral way of saying someone is not showing due respect.
* Discourteous: This is a more formal term for being impolite.
To choose the best replacement, consider the specific situation and the intended tone of your writing.