Very long time in row, like jungle king (7)
I believe the answer is:
leonine
'very long time in row like jungle king' is the definition.
I can't tell whether this defines the answer.
'very long time in row' is the wordplay.
'very long time' becomes 'eon' (an extremely long period of time).
'in' is an insertion indicator.
'row' becomes 'line' (as in a row of things).
'eon' inserted inside 'line' is 'LEONINE'.
Can you help me to learn more?
(Other definitions for leonine that I've seen before include "Imposing like a lion" , "Like a big cat" , "Like a wild animal" , "None lie (anag) - like a lion" , "As a maned animal" .)