Eager, bringing forward new joint (4)
I believe the answer is:
knee
'joint' is the definition.
(I know that knee is a type of synovial joint)
'eager bringing forward new' is the wordplay.
I cannot really understand how this works, but
'new' could be 'n' (common abbreviation eg NT for New Testament) and 'n' is found within the answer.
The remaining letters 'kee' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for knee that I've seen before include "Technical name for this joint is genu" , "middle part of leg" , "Major joint in leg" , "Lower limb joint" , "Genuflector?" .)