To engage in social activities or interact with others for pleasure or companionship. She loves to socialize with her colleagues after work.
To make someone behave in a way that is acceptable to their society. Parents often socialize their children to follow cultural norms.
To convert a private industry or business to government ownership or control. The government decided to socialize the healthcare system to ensure equal access for all citizens.
To acclimate an animal to human presence or to other animals so that it behaves in a socially acceptable manner. Volunteers help socialize the shelter kittens so they will be friendly with new owners.