a.

1. 孤独的，单独的
   When his wife died, he was very lonely.

   太太死后他非常孤独。

2. 寂寞的，孤寂的
   He felt almost intolerably lonely.

   他感到几乎难以忍受的寂寞。

3. 偏僻的，人迹罕至的
   a lonely mountain village

   荒凉的山村

adj.

1. sad because one has no friends or company.
   ▸solitary.
2. (of a place) unfrequented and remote.