Slow absorption I found in very big Scottish bog (7)
I believe the answer is:
osmosis
'slow absorption' is the definition.
'osmosis' can be an answer for 'absorption' (I have seen 'Gradual absorption ' mean 'osmosis' so perhaps 'absorption' could also mean 'osmosis'). I'm unsure of the 'slow' bit.
'i found in very big scottish bog' is the wordplay.
'found in' is an insertion indicator.
'very big' becomes 'os' (abbreviation for outsize).
'scottish bog' becomes 'moss' (I can't justify this - if you can you should give a lot more credence to this answer).
'os'+'moss'='osmoss'
'i' put within 'osmoss' is 'OSMOSIS'.
Can you help me to learn more?
(Other definitions for osmosis that I've seen before include "Becoming absorbed" , "Gradual flow" , "Something like dialysis" , "Diffusion; assimilation" , "absorbing process" .)