Fǽr
Bosworth & Toller Anglo-Saxon Old English Dictionary - fǽr
According to the Old English Dictionary:
fér, es;
- fǽr
- m. A fever; febris :-- Wið þriddan dæges fǽre and feórþan dæges fǽre for a third day's fever and a fourth day's fever, L. M. cont. 1, 62; Lchdm. ii. 12, 27.