Fault that big-headed stupid male! (5)
I believe the answer is:
blame
'fault' is the definition.
('blame' can be a synonym of 'fault')
'big-headed stupid male' is the wordplay.
'big-headed' becomes 'b' (this could be a standard abbreviation which I don't know about).
'stupid' indicates anagramming the letters (in a stupid order).
'male' is an anagram of 'lame'.
'b'+'lame'='BLAME'
'that' acts as a link.
Can you help me to learn more?
(Other definitions for blame that I've seen before include "Inculpate" , "Hold (a person) responsible" , "Impute fault to" , "Accountability" , "Attribute fault or guilt to" .)