Messenger is absorbed by game that's fast (10)
I believe the answer is:
changeless
'fast' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'messenger is absorbed by game' is the wordplay.
'messenger' becomes 'angel' (heavenly messenger).
'is absorbed by' is an insertion indicator.
'game' becomes 'chess' (board game).
'angel' inserted inside 'chess' is 'CHANGELESS'.
'that's' is the link.
Can you help me to learn more?
(Other definitions for changeless that I've seen before include "Consistent" , "same as always" , "Very steady" .)