Listen to (4)
'listen to' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for heed that I've seen before include "Take note of" , "Obey" , "Careful attention" , "Attend to, mind" , "Take account of" .)
'listen to' is the definition.
(to hear something is to listen to it)
This is all the clue.
(Other definitions for hear that I've seen before include "Try (in court)" , "Hark" , "attend" , "Catch" , "to judge" .)