unaccustomed
US /ˌʌn.əˈkʌs.təmd/
UK /ˌʌn.əˈkʌs.təmd/

1.
not familiar or usual; out of the ordinary
:
•
He felt an unaccustomed sense of peace.
•
It was an unaccustomed sight to see him so quiet.
2.
not used to something; not in the habit of
:
•
She was unaccustomed to such luxury.
•
He found himself unaccustomed to the cold weather.