Signalling plan, heroes excited about that (9)
I believe the answer is:
semaphore
'signalling' is the definition.
'plan heroes excited about that' is the wordplay.
'plan' becomes 'map' (I've seen this before).
'excited' is an anagram indicator.
'about that' indicates putting letters inside.
'heroes' anagrammed gives 'sehore'.
'map' placed into 'sehore' is 'SEMAPHORE'.
(Other definitions for semaphore that I've seen before include "Old flag signalling system" , "flagging" , "Way to signal" , "Old communications system" , "See arm hop in signalling system" .)