Wiktionary
vb. (present participle of smart off English)
Usage examples of "smarting off".
He had offended his mentor with that Klansman slur, then compounded the insult by smarting off.
It had taken four years after that day to relearn the art of smarting off.
Late one afternoon, the three o'clock bell fast approaching, she had been in the process of reminding the class of the homework assignment, and Edward had been smarting off in the usual way, and Miss Robbie had, just when the bell began to ring, thrown a chalk eraser at him.
The little rascal was famous for what Bell always referred to as 'smarting off' at such meetings but in this one he hadn't made a sound.
Leatherlungs called me a blockhead twice and made Georgie Sanders stand with his nose pressed against a circle on the blackboard for smarting off.
Estelle has been gone for more than an hour, and you need to stop smarting off and find her before something terrible happens.
Blade got his ass thrown to the crocodiles for smarting off to the priests back in his home country.