Saxophonist's first recently to hide fitting round mouthpiece? (4,6)
I believe the answer is:
soft palate
'mouthpiece?' is the definition.
'saxophonist's first recently to hide fitting round' is the wordplay.
'first' says to take the initial letters.
'recently' becomes 'oflate' ('of late' can be a synonym of 'recently').
'to hide' is an insertion indicator.
'fitting' becomes 'apt' (I've seen this before**).
'round' says the letters should be written in reverse.
The first letter of 'saxophonists' is 's'.
'apt' back-to-front is 'tpa'.
'oflate' going around 'tpa' is 'oftpalate'.
's'+'oftpalate'='SOFT PALATE'
(Another definition for soft palate that I've seen is " Muscular flap used in swallowing or speaking".)