Sickeningly obsequious (7)
I believe the answer is:
fulsome
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sickeningly obsequious</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fulsome that I've seen before include "Excessively ingratiating - of mules (anag)" , "Sickeningly obsequious" , "Excessively flattering (praise)" , "Generous, abundant" , "Excessive (praise)" .)