Apt to break into curt parlance (6)
I believe the answer is:
snappy
'apt' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'break into curt parlance' is the wordplay.
'break' becomes 'nap' (I've seen this in another clue).
'into' indicates putting letters inside.
'curt parlance' becomes 'spy' (I can't justify this - if you can you should believe this answer much more).
'nap' placed within 'spy' is 'SNAPPY'.
'to' is the link.
Can you help me to learn more?
(Other definitions for snappy that I've seen before include "Bad-tempered" , "Quick and energetic" , "bad tempered" , "Informally brisk" , "sort of dresser" .)