Suddenly attack someone physically attractive (4,2)
I believe the answer is:
turn on
'suddenly attack' is the definition.
'turn on' can be an answer for 'attack' (thesaurus). I am not sure about the 'suddenly' bit.
'someone physically attractive' is the wordplay.
I cannot really see how this works, but
'someone' could be 'rn' (RN is an example) and 'rn' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for turn on that I've seen before include "Cause of excitement" , "Person or thing with the ability to excite" , "Start working" , "Set in operation" , "Excite sexually" .)