A trinket or piece of bric-a-brac; A precious item saved and used in regifting, from Lord of the Rings: "Anything that Hobbits had no immediate use for, but were unwilling to throw away, they called a mathom
The term mathom rings a bell from a Tolkien term in The Lord of the Rings " . . . anything that Hobbits had no immediate use for, but were unwilling to throw away, they called a mathom. "
There are a number of institutions that can be figured out from the books. There is a post office, as letters were delivered. There is the Mathom House, a sort of museum where Bilbo sent his chain mail and sword for a while. There are green grocers as well as inns.