Conservative lied at first — now in trouble, the buffoon (5)
I believe the answer is:
clown
'the buffoon' is the definition.
(synonyms)
'conservative lied at first now in trouble' is the wordplay.
'at first' says to take the initial letters.
'in trouble' indicates anagramming the letters.
The initial letters of 'conservative lied' is 'cl'.
'now' is an anagram of 'own'.
'cl'+'own'='CLOWN'
(Other definitions for clown that I've seen before include "Comic entertainer; fool" , "Clumsy fool" , "Funny person in circus" , "Jester" , "Circus comedian" .)