My memory has served up a recollection of the etymology of the Italian province of Lombardy which was originally known as Longobardy, meaning "Long Beard", referring to the custom of the land whereby men wore beards. These people were known for their ability as woodworkers and they made furniture. I believe that the word "lumber" was an old term for furniture and came from the name for the makers. A store room in a home then became known as the "lumber room" and from there, the word for the raw material from which furniture was made was an easy transition so from "long beards" to "lumber" by way of furniture.

Sourdough