Most important person, as anaesthetist, single (6,3)
I believe the answer is:
number one
'most important' is the definition.
(I've seen this before)
'person as anaesthetist single' is the wordplay.
I cannot quite see how this works, but
'person' could be 'one' (I've seen this in other clues) and 'one' is present in the answer.
The remaining letters 'number' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for number one that I've seen before include "Cut" , "arch" , "Top-of-the-charts hit" , "Wee" , "top man?" .)