One of the elements taking Jason’s ship north (5)
I believe the answer is:
argon
'one of the elements' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'jason's ship north' is the wordplay.
'jason's ship' becomes 'argo' (I've seen this before).
'north' becomes 'n' ('N' can be a synonym of 'north').
'argo'+'n'='ARGON'
'taking' acts as a link.
Can you help me to learn more?
(Other definitions for argon that I've seen before include "Inert gas in atmosphere" , "Inert gas used in light bulbs" , "rare gas" , "Gas, 1% of atmosphere" , "Noble gas used in light bulbs" .)