Show maturity, collared by quiet worker (7)
I believe the answer is:
pageant
'show' is the definition.
(thesaurus)
'maturity collared by quiet worker' is the wordplay.
'maturity' becomes 'age' (I've seen this before).
'collared by' means one lot of letters goes inside another (I've seen this in other clues).
'quiet' becomes 'p' (music symbol for 'piano').
'worker' becomes 'ant' (worker is a type of ant).
'p'+'ant'='pant'
'age' going within 'pant' is 'PAGEANT'.
(Other definitions for pageant that I've seen before include "entertaining spectacle" , "Colourful display or parade" , "elaborate display" , "Series of tableaux etc" , "Scene moving" .)