Vein in the neck (7)
I believe the answer is:
jugular
'vein in the neck' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for jugular that I've seen before include "Large 24 in neck" , "Large vein in the neck" , "Vein (go for it!)" , "Type of 25" .)