Expert bringing coaster into use (10)
I believe the answer is:
consummate
'expert' is the definition.
(thesaurus)
'coaster into use' is the wordplay.
'coaster' becomes 'mat ' (I've seen this before).
'into' indicates putting letters inside.
'use' becomes 'consume' (I can't justify this - if you can you should give a lot more credence to this answer).
'mat' placed into 'consume' is 'CONSUMMATE'.
'bringing' acts as a link.
Can you help me to learn more?
(Other definitions for consummate that I've seen before include "total" , "Supreme, perfect; make (a marriage) complete" , "Showing great skill and flair" .)