Over-ready to shoot (7-5)
I believe the answer is:
trigger-happy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">over-ready to shoot</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 trigger-happy that I've seen before include "inclined to recklessness" , "Over-ready to shoot" , "Quick to use a gun" , "Over-enthusiastic with a gun" , "Irresponsible with firearms" .)