Absurd or foolish (4)
I believe the answer is:
daft
I believe this is a double definition.
'absurd' is the first definition.
(thesaurus)
'foolish' is the second definition.
(I've seen this before)
(Other definitions for daft that I've seen before include "'Silly, foolish (4)'" , "'---- as a brush': dotty" , "Informally silly or foolish" , "Informally silly or crazy" , "Scatty" .)