Fieldsian expletive (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fieldsian expletive</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 drat that I've seen before include "Blow!" , "blast" , "Expression of mild annoyance" , "Informal expression of annoyance" , "Darn it!" .)