sheet - A rope used to pull in or let out the sail

sculling - repeated movement of the helm not necessary for steering (42.2 d)

spar - A metal or wooden rod such as mast or boom

square knot - The knot often used to tie up a package.

starboard - The right hand side of the boat when facing forward.

starboard tack - When the boom is on the port side of the boat.

Start - A boat starts when, having been entirely on the pre-start side of the starting line at or after her starting signal, and having complied with rule 30.1 if it applies, any part of er hull, crew of equipment crosses the starting line in the direction of the first mark.  (ISAF Rules)

step - To put up the mast.

stern - The back of the boat.

tack - (1) To turn when the wind is from the front. (2) Being on starboard or port tack. (3) The front lower corner of the sail.

Tack, Starboard of Port - A boat   is on the tack, starboard or port,  corresponding for her windward side.  (ISAF Rules)

tell tale - A device which tells you where the wind is coming from.

tiller - The handle used to steer the boat

tiller extension - A rod which makes the tiller longer. Usually there is a flexible joint between the tiller and the tiller extension.

transom - The back end of the boat.

trim - To adjust the position of the sail to make the boat go faster.port

tune - To adjust the sails and rigging.

three boat length circle - A circular area with a radius of three boat lengths.  If an overlap is established before the leading boat enters this circle, the overlapping boat has the right of way until it passes the mark.