Over the phone, deal in cooked meat for cooler friend (8)

'cooler friend' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'over the phone deal in cooked meat' is the wordplay.
'over the phone' indicates a 'sounds like' (homophone) clue (how it might sound over the phone).
'deal in' becomes 'sell' (synonyms).
'cooked' indicates an anagram (letters cooked into a new form).
'sell' is a homophone of 'cell'.
'meat' with letters rearranged gives 'mate'.
'cell'+'mate'='CELLMATE'

'for' is the link.

Can you help me to learn more?