Big jump (4)
I believe the answer is:
leap
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">big jump</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for leap that I've seen before include "Jump a long way" , "as 1984 was" , "some years?" , "Jump; type of year" , "vault" .)