Unaccompanied (adjective)

Not accompanied by anyone or anything else; done or occurring alone.

Origin:

From the word accompany meaning "to go with", and the prefix un- meaning not.

Examples:

1. He decided to make the trip unaccompanied.
2. She performed the song unaccompanied on the piano.
3. The unaccompanied minor was allowed to fly with a letter from his parents.
4. The unaccompanied asylum seeker was granted asylum in the country.
5. The unaccompanied hike was challenging but also rewarding.