Cocky, boofheaded and old like the generals (4,2,5)
I believe the answer is:
bold as brass
'cocky boofheaded' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'old like the generals' is the wordplay.
I cannot really understand how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
'like' could be 'as' and 'as' is located in the answer.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Another definition for bold as brass that I've seen is " Utterly unabashed".)