unaccompanied

US /ˌʌn.əˈkʌm.pən.id/
UK /ˌʌn.əˈkʌm.pən.id/
1.

not having anyone with you when you go somewhere:

:
•
The airline's policy on unaccompanied minors states that children aged 5 to 7 can fly only on direct and nonstop flights.