Armed vessel (7)
I believe the answer is:
gunboat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">armed vessel</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for gunboat that I've seen before include "Vessel (involved in a type of diplomacy?)" , "Naval symbol of aggression" , "Not a bug (anag)" , "Small naval ship" , "Small military ship" .)