Fa is a noun. It is the 4th note of the music scale. It begins with the letter f.
Some Halloween words beginning with F are:funfairiesfudgefirelightfrightfulfavorsfall
foxy
flaccid
Fork.
foul
Furious
One word that starts with "F" that describes a leader is Fair.
flyleaf
Festival, fair
flesh ?
faults
feature