Nautical direction (4)
'nautical direction' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alee that I've seen before include "On ship's sheltered side" , "Nautical term" , "On the sheltered side (of a ship)" .)
(Other definitions for avast that I've seen before include ""stop" signal" , "eleven [CEASE] at sea" , "Stop at sea" , "Stop! (naut.)" , "Hold fast! (naut.)" .)