Assimilate, soak up (6)
I believe the answer is:
absorb
I believe this clue is a double definition.
'assimilate' is the first definition.
(I know that assimilate can be written as absorb)
'soak up' is the second definition.
(synonyms)
(Other definitions for absorb that I've seen before include "Understand" , "Soak up - engross" , "Take in, water or knowledge" , "Assimilate, integrate" , "Assimilate or soak up" .)