smooth talk; glib tongue; flattery designed to deceive
Refers to eloquent or flattering speech used to manipulate or trick someone. Often carries a negative connotation of insincerity. Related to the expression 舌先三寸.
See also: 舌先三寸
I was taken in by his smooth talk and ended up signing the contract.
You mustn't deceive people with a glib tongue.
Literally 'three inches of tongue', an idiomatic phrase suggesting that a mere three inches of the tongue can produce enough eloquence or flattery to deceive. The exact origin is uncertain, but it is a traditional Japanese metaphor for glibness.