Flash is short about a cry of pain (5)
I believe the answer is:
showy
'flash' is the definition.
(both can mean fancy or impressive)
'short about a cry of pain' is the wordplay.
'short' becomes 'shy' (I've seen this in other clues).
'about' is an insertion indicator.
'a cry of pain' becomes 'ow' (exclamation of pain).
'shy' going around 'ow' is 'SHOWY'.
'is' is the link.
(Other definitions for showy that I've seen before include "Strikingly bright" , "Colourful, ostentatious" , "Flamboyant" , "Ostentatious, bright" , "Strikingly colourful" .)