Fash, trouble.
Fashious, troublesome.
Faut, fault.
Feck, part, the greater part.
Feckless, spiritless.
Fend, defence.
Fern-seed. Certain kinds were supposed to render invisible those who carried it on their person.
Feuar, one who holds lands in feu—i.e., on lease.
File, foul.
Flee, a fly.