孤寂用英语可以翻译为 "loneliness"。这个词来源于英语单词 "lone"，意思是 "独自的"。

例句：

The old man felt a deep sense of loneliness after his wife passed away. (这个老人在他妻子去世后感到了深深的孤寂之感。)

She was surrounded by people, but still felt lonely. (她身边有很多人，但仍然感到孤寂。)

希望以上回答能够帮到您。