Unfamiliar
Unknown
Unusual
Synonyms: Unusual, unconventional, different, alternative, odd, curious, uncharacteristic, abnormal, aberrant, uncommon, novel, exotic, unorthodox, peculiar, atypical, unwonted, anomalous, and out of the ordinary.
Unacquainted with
Synonyms: Unacquainted with, unaccustomed to, unpractised in, unskilled in, uninformed about, ignorant of, new to, strange to, unaware of, nescient of, unused to, unconversant with, inexperienced in, unversed in, unenlightened about, uninitiated in, fresh to, a stranger to, and in the dark about.
Example Sentences
The street looked unfamiliar to me at night.
She felt uncomfortable in the unfamiliar surroundings.
The language sounded unfamiliar, but she tried to understand.
The concept was unfamiliar to most of the students.
He faced an unfamiliar challenge at work today.