mathom

The story

1. Proto-Germanic · derived from*maiþmaz“present, gift”
2. Old English · learned borrowing frommāþum“treasure, object of value, jewel, ornament, gift”
3. English todaymathom

Learned borrowing from Old English māþum (“treasure, object of value, jewel, ornament, gift”), from Proto-Germanic *maiþmaz (“present, gift”); introduced by J. R. R. Tolkien in The Lord of the Rings with the conceit that it was a translation of his invented language Adûni's kast, a word used by Hobbits as a generic name for items which they were unwilling to throw away, but for which they had no use.