Word with happy or rush (4)
I believe the answer is:
hour
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">word with happy or rush</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 hour that I've seen before include "Sixty minutes" , "3,600 seconds" , "Three thousand and six hundred seconds" , "A 24th of a day" , "60 minutes" .)