Sailors can cordon off area fast (7)
I believe the answer is:
abstain
'fast' is the definition.
(I've seen this in another clue)
'sailors can cordon off area' is the wordplay.
I cannot really see how this works, but
'sailors' could be 'abs' (AB is short for able seaman) and 'abs' is located in the answer.
'area' could be 'a' (maths abbreviation) and 'a' is present in the answer.
'can' could be 'tin' (both are metal containers) and 'tin' is found in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for abstain that I've seen before include "Spare" , "Refuse to imbibe" , "Go without" , "Refrain (from drink)" , "Withhold one's vote" .)