Stop, at sea (5)
'stop at sea' is the definition.
(nautical term for 'stop')
This is all the clue.
(Other definitions for avast that I've seen before include "eleven [CEASE] at sea" , "Stop! (naut.)" , "Stop at sea" , "shout stopping the ship" , ""stop" signal" .)
'stop at sea' is the definition.
(nautical term for 'stop')
This is the entire clue.
(Other definitions for belay that I've seen before include "Stop" , "Make fast" , "Turn a rope round something to secure it" .)