Great support for worker? (3,4,5)
I believe the answer is:
the bees knees
'great support' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'worker?' is the wordplay.
I cannot really understand how this works, but
'worker?' could be 'bee' (a worker bee) and 'bee' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
(Other definitions for the bees knees that I've seen before include "Outstandingly good thing" , "Just the very best" , "joints used to crawl with insects?" , "Excellent thing" , "A corker, a humdinger" .)