Knife's flipped egg a doctor eats (6)
I believe the answer is:
dagger
'knife's' is the definition.
(dagger is a kind of knife)
'flipped egg a doctor eats' is the wordplay.
'flipped' says the letters should be written in reverse.
'doctor' becomes 'd' (eg in PhD, Doctor of Philosophy).
'eats' becomes 'r' (I can't justify this - if you can you should believe this answer much more).
'egg'+'a'+'d'='eggad'
'eggad' written backwards gives 'dagge'.
'dagge'+'r'='DAGGER'
Can you help me to learn more?
(Other definitions for dagger that I've seen before include "Murder weapon" , "''Is this a ... which I see before me'' (Macbeth)" , "Hand weapon" , "Short knife for stabbing" , "'Short, double-edged blade (6)'" .)