halsbók (ON) hálsbók (ON) noun

Possibly a ‘neck-book’ or a ‘health-book’. The Old English cognate heálsbōc has been identified as the latter, a protective amulet or phylactery. A halsbók may have been a small book containing prayers for private use. In Grg Þsþ 42 it is specified that when swearing on a book, it must be larger than a halsbók.

prayer book OIce Grg Þsþ 42, 46 Ómb 129 Refs:

Bosworth & Toller s.v. heálsbōc; CV s.v. hálsbók; Fr; GrgTr I:82−83; Páll Vídalín 1854 s.v. háls-bók