1. not being watched or supervised; left alone
2. not dealt with or taken care of

Examples

• The unattended luggage was removed by security.
• Children should never be left unattended in a car.
• The fire started from an unattended candle.
• Several unattended issues remain on the agenda.
• The garden looked overgrown and unattended.
• Unattended pets are not allowed in the store.
• The meeting ended with many questions unattended.