Teat (6)
I believe the answer is:
nipple
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">teat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that teat can be written as nipple)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for nipple that I've seen before include "flow regulator" , "Chest projection" , "Teat" , "private area" , "Oil supplier" .)