Double-jawed words of encouragement (4-4)
I believe the answer is:
chin-chin
'double-jawed words of encouragement' is the definition.
I can't tell whether this defines the answer.
'double-jawed words' is the wordplay.
'double' says to double the letters.
'jawed words' becomes 'chin' (I can't explain this - if you can you should give a lot more credence to this answer).
'chin' duplicated is 'CHIN-CHIN'.
Can you help me to learn more?
(Other definitions for chin-chin that I've seen before include "Down the hatch!" , "Cheers, bottoms up" , "good health ..." .)