Blood pumps a suit (6)
I believe the answer is:
hearts
This might be a double definition.
'blood pumps' is the first definition.
'hearts' can be an answer for 'pumps' ('heart' can be a synonym of 'pump'). I'm not sure about the 'blood' bit.
'a suit' is the second definition.
(hearts is a playing card suit)
Can you help me to learn more?
(Other definitions for hearts that I've seen before include "Body pumps" , "not clubs" , "quarterdeck?" , "Card game and centres of emotions, it's said" , "See 23" .)