In irons:

A vessel is said to be in irons when caught head to wind and unable to pay off on either tack.

Jibs:

A triangular sail set forward of the mast.

Knot:

One nautical mile per hour.

Leech:

The after side of a fore and aft sail, and the outer sides of a spinnaker.

Lee Side:

The side away from the wind direction.

Luff:

To go closer to the wind; also the forward edge of a sail.

Pitching:

A boat’s movement in a fore and aft direction.

Port:

The left-hand side of a boat looking forward.

Port Tack:

To sail with the wind on the port side before the beam.

Rake:

The angle, in relation to the perpendicular, of a boat’s mast which can be raked forward or aft.

Reach:

The course of a sailing boat with the wind aft of close-hauled and forward of running.

Reefing:

Reducing a sail area by taking it in at the reefing points.

Running rigging:

Rigging which is not standing, e.g. halyards, lifts and vangs.