What does "assimilate" mean?

Additional senses

1. 2.To appropriate and transform or incorporate into the substance of the assimilating body; to absorb or appropriate, as nourishment; as, food is assimilated and converted into organic tissue. Hence also animals and vegetables may assimilate their nourishment. Sir I. Newton. His mind had no power to assimilate the lessons. Merivale.
2. 3.To become similar or like something else. [R.]
3. 4.To change and appropriate nourishment so as to make it a part of the substance of the assimilating body. Aliment easily assimilated or turned into blood. Arbuthnot.
4. 5.To be converted into the substance of the assimilating body; to become incorporated; as, some kinds of food assimilate more readily than others. I am a foreign material, and cannot assimilate with the church of England. J. H. Newman.