Faces simpletons (4)

I believe the answer is:

mugs

I believe this clue is a double definition.

'faces' is the first definition.
(I know this)

'simpletons' is the second definition.
(both can mean gullible people)

(Other definitions for mugs that I've seen before include "Faces (sl.)" , "Gullible people" , "Cylindrical cups without saucer" , "'Cups, faces and fall guys (4)'" , "fools and > grimaces" .)

I've seen this clue in The Everyman puzzle in The Observer.

Want a hint initially instead of a full solution? Install my app