A fleet of warships (6)
I believe the answer is:
armada
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a fleet of warships</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 armada that I've seen before include "Spanish fleet sent in 1588 to escort an invasion of England" , "Fighting unit" , "Fleet of armed ships" , "Navy" , "1588 sea battle" .)