someone or something that is unaccompanied has no one with them [↪ accompany]:
Unaccompanied children are not allowed on the premises.
unaccompanied bag/luggage etc
The airport X-rays all unaccompanied baggage.
Many large Third World cities have arisen unaccompanied by national industrial growth.
an unaccompanied singer or musician sings or plays alone [↪ accompaniment, accompanist]:
Lizzie sang unaccompanied.
works for unaccompanied violin