Functionality (7)
I believe the answer is:
utility
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">functionality</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for utility that I've seen before include "Practicality - public service" , "Supplier of gas or electricity" , "Eg, gas supplier" , "Service such as electricity or water" , "A useful thing like electricity company?" .)