cheesy grin
noun
Informal attributive Denoting a broad, uninhibited smile, frequently an exaggerated grin usually perceived as artificial, ingratiating, or insincere; especially in cheesy grin.
- The frequent implication of disingenuousness suggests the influence of two earlier senses: the forced smile induced by ‘saying cheese’ when photographed, and the later use meaning ‘hackneyed, sentimental’..
Origin
1970s; earliest use found in The Observer.