Leader leaves men in dry shelter (4)
I believe the answer is:
tent
'shelter' is the definition.
(canvas shelter)
'leader leaves men in dry' is the wordplay.
'leader leaves' means to remove the first letter.
'in' means one lot of letters goes inside another.
'dry' becomes 'tt' (short for teetotal - no alcohol).
'men' with its first letter taken off is 'en'.
'en' inserted inside 'tt' is 'TENT'.
(Other definitions for tent that I've seen before include "Camping shelter" , "Marquee" , "Temporary shelter" , "Collapsible shelter" , "Temporary residence" .)