Port in case served up by nurse (6)
I believe the answer is:
ostend
'port' is the definition.
(I've seen this before)
'in case served up by nurse' is the wordplay.
'in case' becomes 'so'.
'served up' says the letters should be written backwards.
'by' means one lot of letters go next to another.
'nurse' becomes 'tend' (I've seen this before).
'so' back-to-front is 'os'.
'os'+'tend'='OSTEND'
(Other definitions for ostend that I've seen before include "Port - doesn't (anag)" , "Port -- stoned (anag)" , "Belgian ferry port" , "European port" , "somewhere in Europe" .)