Dress I put on about spring (6)
I believe the answer is:
origin
'spring' is the definition.
(I've seen this in another clue)
'dress i put on about' is the wordplay.
'dress' becomes 'rig' (rig is a kind of dress).
'put' means one lot of letters go next to another.
'about' means one lot of letters goes inside another.
'rig'+'i'='rigi'
'rigi' inserted into 'on' is 'ORIGIN'.
(Other definitions for origin that I've seen before include "Beginning (of species?)" , "Place or point of beginning (6)" , "Source - provenance" , "base" , "Genesis" .)