Secretary brought over card with dispatch (5)
I believe the answer is:
apace
'with dispatch' is the definition.
(I've seen this in another clue)
'secretary brought over card' is the wordplay.
'secretary' becomes 'PA' (abbreviation for personal assistant).
'brought over' says the letters should be written backwards.
'card' becomes 'ace' (ace is a type of playing card).
'pa' reversed gives 'ap'.
'ap'+'ace'='APACE'
(Other definitions for apace that I've seen before include "fast" , "at high speed" , "Quick" , "What's quickly" , "Swiftly, quickly" .)