Fain, glad, willing, full of desire. Sometimes used as an adverb meaning "willingly," e.g. "They fain would go aland."
Fair-speech-masters, men skilled in poetry. There were professional singers and poets called skalds among the northern people, and the power to make verses and to sing was cultivated among the mass of the people and was fairly common.
Fallow, lying quiet, inactive, not bearing crops. The expression, "fallow bondage," means a bondage of sleep and idleness.
Fare, to travel. Sometimes when joined to adverbs it means to prosper, e.g. to fare ill, to fare well, how does he fare?
Fashion, to make, to arrange. Regin hoped to be the world's "fashioning lord," that is, the supreme king and orderer of all things.
Fell-abiding folk, men who worked at home instead of going out to battle.
Flame-blink, the flash of light from the fire round Brynhild's home.
Flaw, defect, fault, e.g. "the hauberk ... clean wrought without a flaw;" "the ring ... that hath ... no flaw for God to mend." If used of rain, it means a slight shower, e.g. "a flaw of summer rain,"
Fleck, spot, mark.
Foam-bow, the small rainbow seen in the spray from a waterfall.