No farewell to learners — in no way! (3,2,3)
I believe the answer is:
not at all
'in no way' is the definition.
(synonyms)
'no farewell to learners' is the wordplay.
'farewell' becomes 'tata' (I have seen 'A Farewell' mean 'ta-ta' so perhaps 'farewell' could also mean 'ta-ta').
'to learners' becomes 'll' (I've seen this in other clues).
'no'+'tata'+'ll'='NOT AT ALL'
(Other definitions for not at all that I've seen before include "By no means - polite disclaimer" , "Anything but!" , "You're welcome" , "Don't mention it!" , "forget it" .)