Whopper somewhat colossal, I expect (3)
I believe the answer is:
lie
'whopper' is the definition.
(I've seen this before)
'somewhat colossal i expect' is the wordplay.
'somewhat' indicates a hidden word.
'LIE' is hidden in the letters of 'colossal i expect'.
(Other definitions for lie that I've seen before include "Falsity" , "Untruth; rest" , "Rest; falsehood" , "situation" , "Perversion of the truth" .)