Acculturation refers to the process by which members of minority groups come to identify with and feel part of the mainstream culture or it refers to the modification of a person's or a group's culture through the influence of the culture of another group.

Other /More definition:
Acculturation refers to the extent to which a person identifies with his or her group of origin and its culture or with the mainstream dominant culture. When a person change to adapt to a new culture.

Other definition:

Acculturation is the process of acquiring or adapting to a new culture, its traditions, customs, and patterns of daily living.