Dave’s outside, wild about Republican postponement (8)
I believe the answer is:
deferral
'postponement' is the definition.
(I know that postponement can be written as deferral)
'dave's outside wild about republican' is the wordplay.
'outside' means to remove the middle letters.
'wild' becomes 'feral' (similar in meaning).
'about' indicates putting letters inside.
'republican' becomes 'R' (abbreviation).
'dave' with its middle taken out is 'de'.
'feral' going around 'r' is 'ferral'.
'de'+'ferral'='DEFERRAL'
(Other definitions for deferral that I've seen before include "Postponement" , "shelving" , "Adjournment" .)