False claim by company is laughable (7)
I believe the answer is:
comical
'is laughable' is the definition.
(synonyms)
'false claim by company' is the wordplay.
'false' is an anagram indicator.
'by' says to put letters next to each other.
'company' becomes 'co' (abbreviation).
'claim' anagrammed gives 'mical'.
'mical' put after 'co' is 'COMICAL'.
(Other definitions for comical that I've seen before include "Rich" , "Amusing or droll" , "'Amusing, funny (7)'" , "Witty" , "Humorous" .)