Hint coming from line, we hear (3)
I believe the answer is:
cue
'hint' is the definition.
(thesaurus)
'line we hear' is the wordplay.
'line' becomes 'queue' (queue is a kind of line).
'we hear' indicates a 'sounds like' (homophone) clue.
'queue' sounds like 'CUE'.
'coming from' acts as a link.
(Other definitions for cue that I've seen before include "Signal for action" , "Snooker rod" , "Reminder to do something" , "State of collapse, disaster" , "Actor's words" .)