Fuel-carrying ship (3,6)
(Other definitions for oil tanker that I've seen before include "On which crude" , "Fuel transport ship" , "Ship carrying fuel" , "boat" , "craft" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fuel-carrying ship</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oiler that I've seen before include "Petroleum tanker" , "One applying lubricant" , "Loire (anag.)" , "it may be 4 [SHIPSHAPE]" , "Grease monkey" .)