Constant point learnt another way (7)
I believe the answer is:
eternal
'constant' is the definition.
(I've seen this before)
'point learnt another way' is the wordplay.
'point' becomes 'e' (E is an example**).
'another way' is an anagram indicator.
'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" .)