Codex:F

Farthest Gate
"The navigational charts, the route to the Farthest Gate."

- Sao Feng

Another name for World's End; possibly the passage leading to that area.

Fid
A tool commonly used by sailors, normally taking the form of a stake or prong made from wood or bamboo. Captain Sao Feng was known to use a fid as a weapon.

Fiddler's Green
"With the keys to the cage, and the devil to pay, / We lay to Fiddler's Green."

- from Hoist the Colours

A paradisiacal land imagined by sailors, possibly as the opposite of Davy Jones' Locker.

Figurehead
"If the figurehead was on Opawiwato, Sterling had to find it; by what ever means necessary."

- Nemesis gunner

A figurehead is a carved wooden decoration, often female or bestial, found at the prow of ships.

Fire in the hole
"Uh, oh! Fire in the hole!"

- Cotton's parrot

A standard warning indicating that an explosive detonation in a confined space is imminent. It originated with miners, who needed to warn their fellows that a charge had been set. Cotton's parrot learned the phrase, and repeated it as Jack the monkey lit a firework in Singapore.

Firebrand
A firebrand is a special type of cannon round that appears in Pirates of the Caribbean Online. When used, a cannon will shoot out a fiery cannonball.

First Mate
Second-in-command to the captain or master of a ship. 

Forecastle
Also fo'c's'le or fo'c'sle:
 * A superstructure at or immediately aft of the bow of a vessel, used as a shelter for stores, machinery, or as quarters for sailors;
 * The forward part of the weather deck of a vessel, commonly that part forward of the foremast.

Foremast
The mast nearest the bow in all ships with two or more masts. 

Forge
Another name for a smithy.

Fountain of Youth
"There's more than one way to live forever. Gents, I give you the Fountain of Youth."

- Hector Barbossa

A mystical water spring intended to restore the youth of anyone who drinks it. Explorer Juan Ponce de León set out to Florida to find it in 1513. Captain Jack Sparrow and Captain Hector Barbossa searched for it in Pirates of the Caribbean: On Stranger Tides.

Funeral
"You don't want to be doing that, mate." "No, I really think I do." "...Your funeral."

- Jack Sparrow and Hector Barbossa

Being related to a ceremony in honor of a deceased person.