have a sharp tongue
US /hæv ə ʃɑrp tʌŋ/
UK /hæv ə ʃɑrp tʌŋ/
1.
to tend to speak in a critical or sarcastic way
:
•
Be careful with her; she tends to have a sharp tongue.
•
Despite his kind appearance, the old man could sometimes have a sharp tongue.