Long spar (4)
I believe the answer is:
yard
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">long spar</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 yard that I've seen before include "Tract of land enclosed for a particular purpose" , "Three feet - detectives?" , "Linear measure" , "compound" , "Dray (anag.)" .)