Chat ends in lengthy tea break (3)
I believe the answer is:
yak
'chat' is the definition.
(thesaurus)
'ends in lengthy tea break' is the wordplay.
'ends in' says to take the final letters (I've seen 'end in' mean this).
The last letters of 'lengthy tea break' are 'YAK'.
(Other definitions for yak that I've seen before include "Idle talk" , "Pack animal" , "Gossip (sl)" , "Blabber" , "Talk incessantly" .)