Panic, finding line on neck (4)
I believe the answer is:
fret
'panic finding line' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'on neck' is the wordplay.
I cannot really understand how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' 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 fret that I've seen before include "Display anxiety" , "Wear; guitar ridge" , "Become unhappy, worry" , "Worry - ridge on guitar's fingerboard" , "Worry; wet mist" .)