The phrase "sharp tongue" refers to someone who often speaks in a harsh or critical manner, using words that can hurt or offend others. Full definition
A hard nosed city known for inhabitants with sharp tongues who love nothing more than a good game of footie, Liverpool does UK culture like few places outside London. (hookupcloud.com)
Hensarling — a polite and low - decibel conservative with a deadpan sense of humor and an occasionally sharp tongue — has become a tea party favorite by relentlessly striving to cut federal spending and shrink the federal government. (courant.com)
They worship his vileness as charm and sharp tongued wit --- but don't you dare cross that line you religious bigotted, intolerant. (nakedpastor.com)