Pressure on nurse to carry on sham (7)
I believe the answer is:
pretend
'sham' is the definition.
(synonyms)
'pressure on nurse to carry on' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'on' says to put letters next to each other.
'nurse' becomes 'tend' (I've seen this before).
'to carry' means one lot of letters goes inside another.
'on' becomes 're' ('on' can be mean 'with reference to').
'p'+'tend'='ptend'
'ptend' enclosing 're' is 'PRETEND'.
(Other definitions for pretend that I've seen before include "make a false claim" , "Imagined" , "Imaginary, make-believe" , "Make believe - imply falsely" , "keep up appearances" .)