The exact meaning of assimilate can depend upon its context. For example:
"assimilate to a new country" — fitting into a prevailing culture
"assimilate the information" — transform information within the mind into understanding
"assimilate the food" — transform nutrients within the body for its use
I believe he is of mine; — I am sure he is — I feel akin to him — I understand the language of his countenance and movements: though rank and wealth sever us widely, I have something in my brain and heart, in my blood and nerves, that assimilates me mentally to him.
Chapter 17 (71% in)
There are no more uses of "assimilate" in Jane Eyre.