Defer turning up? Swell (3,3)
I believe the answer is:
put off
'defer' is the definition.
(synonyms)
'turning up? swell' is the wordplay.
'turning' says the letters should be written in reverse.
'swell' becomes 'toff' (wealthy or high-class person).
'up' back-to-front is 'pu'.
'pu'+'toff'='PUT-OFF'
(Other definitions for put off that I've seen before include "Postpone or dissuade" , "Don't encourage - delay" , "Throw" , "confuse" , "Dissuaded - discouraged" .)