What is the meaning of Lighten?

To make brighter or clearer; to illuminate.

To become brighter or clearer; to brighten.

To flash lightning, to give off lightning.

To emit or disclose in, or as if in, lightning; to flash out, like lightning.

To illuminate with knowledge.

To alleviate; to reduce the burden of.

To make light or lighter in weight.

To make less serious or more cheerful.

To become light or lighter in weight.

To become less serious or more cheerful.

To descend; to light.

Source: wiktionary.org