Be there for a tiptop nurse (6)
I believe the answer is:
attend
'be there' is the definition.
(I've seen this before)
'a tiptop nurse' is the wordplay.
'tiptop' becomes 't' (top of the word 'tip').
'nurse' becomes 'tend' (tend can mean to nurse or look after).
'a'+'t'+'tend'='ATTEND'
'for' is the link.
(Other definitions for attend that I've seen before include "Escort (someone)" , "Listen carefully" , "Be present at, turn up" , "Go regularly to (school)" , "Be present or appear at" .)