1. in the sense of isolated
- alone
- isolated
- friendless
- all alone
- without friends/companions
- companionless
- outcast
- with no one to turn to
- abandoned
- forsaken
- unloved
- rejected
- unpopular
- unwanted
- unhappy
- sad
- despondent
- forlorn
- lonesome
2. in the sense of solitary
- unaccompanied
- solitary
- lone
- alone
- without companions
- by oneself/itself
- companionless
3. in the sense of deserted
- uninhabited
- deserted
- unpopulated
- unfrequented
- barren
- desolate
- remote
- isolated
- secluded
- out of the way
- off the beaten track
- sequestered
- in the middle of nowhere
- in the back of beyond
- lone
- godforsaken
Example Sentences of Lonely
1. He felt lonely in the crowd.
2. The empty house seemed very lonely.
3. She spends her evenings feeling lonely.
4. A lonely heart seeks companionship.