Dining room (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dining room</span>' is the definition.<br/ ><span class="explanation-format__explanation">(mess hall is a kind of dining room)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Another definition for mess hall that I've seen is " where soldiers eat".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dining room</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for canteen that I've seen before include "Flask - restaurant attached to institution" , "Office eating area" , "Water container and works restaurant" , "Workers' cafe and cutlery box" , "Workplace eatery" .)