Effortless assimilation (7)
I believe the answer is:
osmosis
'effortless assimilation' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for osmosis that I've seen before include "Gradual flow" , "picking up slowly" , "Diffusion of liquid through porous barrier" , "absorbing process" , "Absorption (biol.)" .)