BROWNING

To become brown.

"Fry the onions until they brown."

To cook something until it becomes brown.

"Brown the onions in a large frying pan."

To tan.

"Light-skinned people tend to brown when exposed to the sun."

The act or operation of giving a brown colour, as to gun barrels, cooked food, etc.

Any of various preparations used to impart a brown colour to gravy, leather, etc.

A smooth coat of brown mortar, usually the second coat, and the preparation for the finishing coat of plaster.