Medicated (5)
I believe the answer is:
dosed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">medicated</span>' is the definition.<br/ ><span class="explanation-format__explanation">(dosing is a kind of medicating)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for dosed that I've seen before include "Treated with medicine" , "Gave medicine to" , "Given medicine" , "Medicated" , "Administered a portion of medicine to" .)