Has he to sit around keeping his mouth shut? (3)
I believe the answer is:
len
'his mouth shut?' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'has he to sit around' is the wordplay.
'has he' becomes 'le' (I can't explain this - if you can you should believe this answer much more).
'to sit' becomes 'scrunch up' (scrunching up is a kind of sitting).
'around' means to look at the middle letters.
The middle letter of 'scrunchup' is 'n'.
'le'+'n'='LEN''
'keeping' acts as a link.
Can you help me to learn more?
(Other definitions for len that I've seen before include "Sir - - Hutton" , "Boy" , "Leonard (dim.)" , "- - Hutton, cricketer" , "-- Deighton, author" .)