Medicate (4)
I believe the answer is:
dose
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">medicate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(dosing is a kind of medicating)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dose that I've seen before include "Medicinal amount" , "Prescribed amount of medicine" , "Measured quantity of medicine" , "Measure of drug" , "Measure (med.)" .)