Imagine each upsetting nurse (7)
I believe the answer is:
pretend
'imagine' is the definition.
(I've seen this before)
'each upsetting nurse' is the wordplay.
'each upsetting' becomes 'pre' (I can't explain this - if you can you should believe this answer much more).
'nurse' becomes 'tend' (tend can mean to nurse or look after).
'pre'+'tend'='PRETEND'
Can you help me to learn more?
(Other definitions for pretend that I've seen before include "Imaginary, make-believe" , "Imagine" , "Suppose" , "Sham" , "keep up appearances" .)