Misguided sour smile (3-4)

I believe the answer is:

off-beam

'misguided' is the definition.
(I've seen this before)

'sour smile' is the wordplay.
'sour' becomes 'off' (synonyms).
'smile' becomes 'beam' (to beam is to smile).
'off'+'beam'='OFF-BEAM'

(Other definitions for off-beam that I've seen before include "Mistaken" , "On the wrong track; awry" , "Inaccurate or misguided" , "Wrong (navigation)" , "On the wrong track (colloq.)" .)

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

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.