How sharp is this partner's second reminder, about to beat clubs (8)

'how sharp is this' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'partner's second reminder about to beat clubs' is the wordplay.
I cannot quite understand how this works, but
'about' could be 'c' (abbreviation for 'circa') and 'c' is found within the answer.
'beat' could be 'tan' (I've seen this before) and 'tan' is found within the answer.
'clubs' could be 'c' (abbreviation used in card games such as bridge) and 'c' is found in the answer.
'partner' could be 'e' and 'e' is located in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?