Almost new party piece, certainly handy (4)
I believe the answer is:
near
'almost' is the definition.
(near can mean almost or virtually)
'new party piece certainly handy' is the wordplay.
I cannot quite understand how this works, but
'new' could be 'n' (common abbreviation eg NT for New Testament) and 'n' is present in the answer.
'piece' could be 'ear' (ear is a kind of piece) and 'ear' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for near that I've seen before include "Close to - stingy - approach" , "Close in time or place" , "Verging on" , "unlikely to spend much?" , "A short distance away" .)