To brag (5)
I believe the answer is:
boast
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">to brag</span>' is the definition.<br/ ><span class="explanation-format__explanation">(to boast is to brag or show off)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for boast that I've seen before include "shot off the side wall" , "Talk conceitedly" , "Blow one's own trumpet" , "Talk big" , "Talk with self-pride" .)