Amusing? How odd! (5)
I believe the answer is:
funny
I believe this is a double definition.
'amusing?' is the first definition.
(thesaurus)
'odd' is the second definition.
(thesaurus)
'how' is the link.
(Other definitions for funny that I've seen before include "Strange; comic" , "Comical" , "Droll -- suspicious" , "Odd - amusing" , "Ha-ha or peculiar?" .)