Language progress comes after cutting connection short (5)
I believe the answer is:
lingo
'language' is the definition.
(lingo is a kind of language)
'progress comes after cutting connection short' is the wordplay.
'progress' becomes 'go' (I've seen this in other clues).
'comes after' is a charade indicator (letters next to each other).
'cutting connection short' becomes 'lin' (I can't justify this - if you can you should give a lot more credence to this answer).
'go' put after 'lin' is 'LINGO'.
Can you help me to learn more?
(Other definitions for lingo that I've seen before include "Unfamiliar language or jargon" , "special words" , "Specialised vocabulary" , "Johnny Foreigner speaks one" , "Jargon, foreign language (informal)" .)