Liquid part of blood (6)
I believe the answer is:
plasma
'liquid part of blood' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for plasma that I've seen before include "State" , "part of donor's contribution?" , "Colourless fluid of the blood and lymph" , "Component of TV screen" , "Clear fluid portion of blood" .)