Ákafr

As defined by A Concise Dictionary of Old Icelandic (Geir Zoëga):

ákafr

a. vehement, fierce (~ bardagi); þenna dag var veizlan allra áköfust, at the highest pitch; neut. as adv., kalla ákaft á Bárð, to pray to B. fervently; ríða sem ákafast, to ride at a furious pace.

Possible runic inscription in Younger Futhark:ᛅᚴᛅᚠᚱ

Also available in related dictionaries:

This headword also appears in dictionaries of other languages closely related to Old Icelandic.

• Old Norse - Cleasby & Vigfusson Dictionary
• Old Norwegian - Johan Fritzner's Dictionary