Like one who supplies bowlers and bats? (3,2,1,6)
I believe the answer is:
mad as a hatter
'like one who supplies bowlers' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'bats?' is the wordplay.
I cannot really see how this works, but
'bats?' could be 'mad' (bats can informally mean mad) and 'mad' is located in the answer.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for mad as a hatter that I've seen before include "Completely foolish" , "Crazy" , "Completely insane (informal)" , "Totally daft" , "Sun-orbiting body" .)