Ridiculous bug has overwhelmed relative (7)
I believe the answer is:
risible
'ridiculous' is the definition.
(thesaurus)
'bug has overwhelmed relative' is the wordplay.
'bug' becomes 'rile' (I've seen this before).
'has' is an insertion indicator.
'overwhelmed relative' becomes 'sib' (sib is a kind of relative. I am not sure about the 'overwhelmed' bit.**).
'rile' going around 'sib' is 'RISIBLE'.
Can you help me to learn more?
(Other definitions for risible that I've seen before include "Laughable, really ridiculous" , "Comical, laughable" , "Absurd" , "Ludicrous, laughable" , "Funny - not even funny" .)