Vessel old drinker's club will grab over empty tumbler on counter (5)
I believe the answer is:
aorta
'vessel' is the definition.
(blood vessel)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for aorta that I've seen before include "Main arterial vessel, carrying blood to the heart" , "Principal artery" , "Blood carrier" , "blood flows from it" , "This carries blood from the heart" .)