The story
- Old Norse · derived fromgersemi
- Old English · derived fromgærsum
- Middle English · inherited fromgersom
- English todaygersum
From Middle English gersom, gersum, from Old English gærsum, gersum, gærsuma, from Old Norse gersemi, gørsemi (“treasure”), from gerr, gǫrr (“ready”) + -semi (“-ness”), with the ending assimilated to native -sum. Compare garrison.
Etymology from Wiktionary, CC BY-SA 4.0.