Insincerely fluent (4)
I believe the answer is:
glib
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">insincerely fluent</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for glib that I've seen before include "Shallowly articulate" , "Superficially facile with words" , "Casually fluent" , "Fluent and plausible" , "Plausibly fluent" .)