Leapt suddenly (6)
I believe the answer is:
sprang
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">leapt suddenly</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 sprang that I've seen before include "got out of jail" , "freed prisoner" , "Leapt foward" , "Lept forward" , "Leaped forward" .)