Not very often (6)
I believe the answer is:
seldom
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not very often</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 seldom that I've seen before include "Only occasionally" , "Not often, infrequently" , "Alluvium" , "Once in a blue moon" , "Models (anag)" .)