Hoar frost (4)
I believe the answer is:
rime
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">hoar frost</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 rime that I've seen before include "Hoarfrost" , "dated poetry" , "Hoar frost" , "Kind of frost in mire" , "''The ... of the Ancient Mariner'' (Coleridge)" .)