Quite good to be back from Korea, etc (4)
I believe the answer is:
okay
'quite' is the definition.
(thesaurus)
'good to be back from korea etc' is the wordplay.
'good' becomes 'ok'.
'to be back from' says to take the final letters (the letter at the back of the word).
'etc' becomes 'y' (I can't justify this - if you can you should give a lot more credence to this answer).
The last letter of 'korea' is 'a'.
'ok'+'a'+'y'='OKAY'
Can you help me to learn more?
(Other definitions for okay that I've seen before include "Authorise" , "Alright" , "in reasonable health?" , "Informally, all right" , "Common jargon for yes, all right" .)