Fall back in a bit of a flap, seemingly (5)
I believe the answer is:
lapse
'fall back' is the definition.
(synonyms)
'bit of a flap seemingly' is the wordplay.
'bit of' says the answer is hidden in the clue.
'LAPSE' can be found hidden inside 'flap seemingly'.
'in a' acts as a link.
(Other definitions for lapse that I've seen before include "Slight error as caused by inattention" , "Careless mistake" , "Error; oversight" , "Decline into an inferior state" , "Decline - pass away" .)