Ring, dainty, being held in reserve (2,3)
I believe the answer is:
on ice
'held in reserve' is the definition.
(I've seen this before)
'ring dainty' is the wordplay.
'ring' becomes 'o'.
'dainty' becomes 'nice' ('nice' can be a synonym of 'dainty').
'o'+'nice'='ON ICE'
'being' is the link.
(Other definitions for on ice that I've seen before include "Where one might find slippers" , "Temporarily suspended" , "Waiting" , "Halted for a while" , "delayed" .)