Joints engineers knocked back in Sandbanks (7)
I believe the answer is:
reefers
'joints' is the definition.
(I know this)
'engineers knocked back in sandbanks' is the wordplay.
I cannot quite see how this works, but
'engineers' could be 're' (abbreviation for Royal Engineers) and 're' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for reefers that I've seen before include "Cannabis cigarettes" , "Nautical jackets" , "Sailors' jackets" , "Jackets; joints" , "Double-breasted jackets" .)