A flimsy perch (6)
I believe the answer is:
alight
'perch' is the definition.
('alight' can be a synonym of 'perch')
'a flimsy' is the wordplay.
'flimsy' becomes 'light' (I've seen this before).
'a'+'light'='ALIGHT'
(Other definitions for alight that I've seen before include "Ignited; get off" , "Leave a vehicle - burning" , "Touch down" , "(Of bird) settle" , "'Step off, a bus, say (6)'" .)