introverted

/ˈɪntrəvɜrtɪd/
adjective
  1. Having a personality type that is more focused on inner thoughts and feelings than on external social activities; preferring solitary or small-group activities to large social gatherings.
    • She is introverted but not unfriendly; she just needs more alone time than most people.
    • My introverted brother would rather spend Saturday night playing video games alone than go to a crowded concert.
    • The introverted student excelled in online classes because she could work at her own pace without social pressure.