A day in Rome (4)
I believe the answer is:
ides
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a day in rome</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Roman calendar term, as in the Ides of March)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ides that I've seen before include "Roman monthly date" , "March day fatal to Julius Caesar" , "Roman calendar day roughly in the middle of the month" , "Eg March 15" , "March 15; dies (anag.)" .)