Today's word is pretty cool. As a matter of fact, you probably use one of these almost every day!
O is for: Octothorpe
An octothorpe is one of these bad boys: #. An octothorpe goes by many names, none really more correct than the next: pound sign, hash sign, hex, sharp, number sign, and even thud in some remote instances. It's really just whatever you prefer to say.
However . . .
Octothorpe is actually the least ambiguous of them all. Pound, hash, hex, sharp, and thud are all homonyms. Octothorpe is not, which makes it the clearest choice! Aren't you glad you now know? :)