Was a nag (6)
I believe the answer is:
carped
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">was a nag</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 carped that I've seen before include "Complained like goldfish?" , "Raised trivial objections" , "Raised petty objections like goldfish" .)