Heaðu-wælm

According to the Old English Dictionary:

-welm; wylm, es;

heaðu-wælm

m. Fierce, intense heat, Cd. 17; Th. 21, 14; Gen. 324: 149; Th. 187, 8; Exod. 148: Beo. Th. 165; B. 82: 5630; B. 2819: Andr. Kmbl. 3082; An. 1544: Elen. Kmbl. 1154; El. 578: 2607; El. 1305. heaðu-wælm