1. sad and lonely, especially from being abandoned or left alone
2. appearing empty, abandoned, or in poor condition
3. having little chance of success; hopeless

Examples

• The lost child looked forlorn standing alone in the crowded mall.
• She felt forlorn after all her friends moved away.
• The forlorn building had broken windows and peeling paint.
• The abandoned playground looked forlorn in the winter snow.
• It was a forlorn hope that the missing hikers would be found alive.
• His forlorn attempt to fix the car only made things worse.
• The forlorn puppy waited by the gate for its owner to return.