Where nurse might put needle, reportedly to no avail? (2,4)
I believe the answer is:
in vain
'to no avail?' is the definition.
('in vain' can be a synonym of 'to no avail')
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for in vain that I've seen before include "Uselessly, to no avail" , "Without effect" , "'To no avail (2,4)'" , "To no end" , "Fruitlessly" .)