Fibber (4)
I believe the answer is:
liar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fibber</span>' is the definition.<br/ ><span class="explanation-format__explanation">(fib means to lie)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for liar that I've seen before include "Person regularly 'economical with the truth'" , "One not telling the truth" , "One telling untruths" , "Untruthful person (Billy in Schlesinger film)" , "Teller of untruths" .)