Constant point learnt another way (7)
I believe the answer is:
eternal
'constant' is the definition.
(I've seen this in another clue)
'point learnt another way' is the wordplay.
'point' becomes 'e' (compass point).
'another way' indicates an anagram.
'learnt' anagrammed gives 'ternal'.
'e'+'ternal'='ETERNAL'
(Other definitions for eternal that I've seen before include "non-stop" , "like Rome?" , "carrying on endlessly" , "Imperishable" , "always to be remembered" .)