Sailor’s confinement (4)
I believe the answer is:
brig
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sailor's confinement</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for brig that I've seen before include "Crew can" , "officer contracted" , "Two-masted square-rigged sailing ship" , "Sailing vessel or lock-up on board" , "A ship; army officer (abbr.)" .)