In time, any man who rushed to fight a fire became known as a fire buff because of the buffalo coat he wore.

VOA: special.2009.05.17

The meaning of buff that we do know about is one that describes a person.

VOA: special.2009.05.17

Someone who is deeply interested in the American Civil War is a Civil War buff.

VOA: special.2009.05.17

A buff is someone who has a strong, special interest in something.

VOA: special.2009.05.17

For example, someone who loves jazz music is a jazz buff.

VOA: special.2009.05.17