Vessel taking a regular part in a circulatory system (7)
I believe the answer is:
jugular
'vessel' is the definition.
(I know that jugular is a vein)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for jugular that I've seen before include "Vein (go for it!)" , "Large 24 in neck" , "Large vein in the neck" , "Type of 25" .)