One against physician tickling nurses (4)
I believe the answer is:
anti
'one against' is the definition.
(I've seen this before)
'physician tickling nurses' is the wordplay.
'nurses' says the answer is hidden in the clue (nurse can mean holding closely).
'ANTI' is hidden in the letters of 'physician tickling'.
(Other definitions for anti that I've seen before include "not favoured" , "on the other side" , "Someone opposed (to a policy?)" , "An opponent - opposed to party policy, etc" , "Prefix meaniing against" .)