Half (4)
(Other definitions for half that I've seen before include "Moiety" , "Short distance - steal!" , "Two of these to the pint" , "proportion" , "one over a couple" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">half</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for semi that I've seen before include "Not detached house" , "Common type of house" , "House attached to one other" , "House joined to another" , "Partly detached home" .)