Sailors' cry (5-2)
'sailors' cry' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for heave-ho that I've seen before include "Dismissal (informal)" , "Rejection" , "Cry to aid physical effort" , "Sailors' call to exertion" , "elbow" .)
'sailor's cry' is the definition.
(nautical term meaning 'stop')
This is all the clue.
(Other definitions for avast that I've seen before include "Stop (nautical)" , "order for tar" , "Stop, nautically speaking" , "Stop on board" , "Stop at sea" .)