Senses
磨牙 to grind one's teeth
To grind the upper and lower teeth together, especially during sleep.
磨牙 to argue pointlessly
To bicker or argue over trifles or to waste one's breath
磨牙 molar
A molar tooth located at the back of the mouth used for grinding food.
磨牙 to chat
To engage in idle gossip or talk about unimportant things