Steal round, say, and fall into place (4,5)
I believe the answer is:
take shape
'fall into place' is the definition.
(thesaurus)
'steal round say' is the wordplay.
'steal' becomes 'take' (to steal is to take without permission).
'round say' becomes 'shape' (rounding is a kind of shaping).
'take'+'shape'='TAKE SHAPE'
'and' acts as a link.
(Other definitions for take shape that I've seen before include "Assume a definite form" , "Materialise, assume substance" , "Develop" .)