How the telephone keypad gave “octothorpe” a job
The name octothorpe became useful when telephones gained two keys that had no counterpart on a traditional rotary dial: * and #. In touch-tone systems, these extra buttons could send signals beyond the digits, giving telephone networks a way to offer features such as menu choices and call controls. People needed names for the new keys, and the symbol now called a hash, number sign, or pound sign acquired another label.
“Octo” is the part with the clearest visual logic: the symbol can be seen as having eight projecting ends. “Thorpe,” however, does not complete a comparably secure technical explanation. Stories have linked it to the surname of athlete Jim Thorpe or to an old word for a village, but the origin is disputed. The appealing neatness of the whole word can make those explanations sound more certain than they are.
A name shaped by the symbol—and by its users
Octothorpe is not the only name for #, and which name people use depends on context. In a phone menu, someone may be told to press the pound key; online, the same mark is commonly called a hashtag when it introduces a searchable topic label. The mark’s role changes, while its shape stays recognizable.
That flexibility is part of why the older, keypad-era name survives: it gives the symbol a distinctive label when “number sign” or “pound sign” might mean something else to the listener. But the word’s history also offers a small lesson in technical vocabulary: a name can have a crisp explanation for one half and a much less settled story for the rest.
