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.

An estimated 30 unaccompanied children arrive at the city's train stations every day.

To everyone's great surprise, the princess arrived at the ball unaccompanied. 令所有人都大吃一惊的是，公主独自一人来参加舞会。

Unaccompanied music is produced by a singer or by someone playing a musical instrument without anyone else singing or playing at the same time.

People are often more capable of good unaccompanied singing than they realize.

She sang the first three verses with a piano and the last verse unaccompanied. 她在钢琴的伴奏下唱了前三节，清唱了最后一节。