Nautical .

a fore-and-aft sail on the aftermost lower mast of a sailing vessel having three or more masts.

a designation given to the mast abaft a mizzenmast, usually the aftermost mast in any vessel.

Informal . a smartly moving person or animal, esp. a fast horse.

Chiefly New England . something remarkably fine.

of or pertaining to a spanker mast or its rigging.