octothorp

1. The official name for the numbers sign that looks like: #
2. The symbol # on a telephone or keyboard.
3. A typographic symbol having two vertical lines intersected by two horizontal lines. It is also called the crosshatch, hash, numeral sign and number sign; in the U. S. it is commonly called the pound sign; especially, to designate the symbol as used on digital telephone dials, but this can be confusing to Europeans who think of the pound sign as the symbol for the British pound. It is commonly used as a symbol for the word number; as in #36 = "number thirty-six".