Jugular nerve out of order, a constriction (10)
I believe the answer is:
bottleneck
'a constriction' is the definition.
('bottleneck' can be a synonym of 'constriction')
'jugular nerve' is the wordplay.
'jugular' becomes 'bottle' (I can't explain this - if you can you should give a lot more credence to this answer).
'nerve' becomes 'neck' (I've seen this before).
'bottle'+'neck'='BOTTLENECK'
'out of order' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
(Other definitions for bottleneck that I've seen before include "Traffic restriction" , "may cause delay" , "Snarl-up" , "hold-up situation" , "Constricted place" .)