Hash (hăsh), n. [Formerly hachey, hachee, F. hachis, fr. hacher to hash; of German origin; cf. G. hippe sickle, OHG. hippa, for happia. Cf. Hatchet.]
1. That which is hashed or chopped up; meat and vegetables, especially such as have been already cooked, chopped into small pieces and mixed.
[1913 Webster]
2. A new mixture of old matter; a second preparation or exhibition.
[1913 Webster]
I can not bear elections, and still less the hash of them over again in a first session. Walpole.
[1913 Webster]
3. Hashish. [slang]
[PJC]
octothorp, octothorpe, n. [octo- eight + thorp Etymology of thorp uncertain. (ca. 1965). See quotes below. Possibly derived from octalthorpe or octotherp (once used by the Bell System?).] 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 (meaning: number thirty-six)”.
[PJC]
For the following explanation, I am indebted to Michael Quinion, whose World Wide Words web site (www.quinion.com/words) is a fascinating and invaluable resource for anyone interested in words and their origins.
Anyone who has ever used a touch-tone telephone has seen the octothorpe. It's that little tic-tac-toe symbol in the lower right corner of the keypad, right across from the asterisk (which the telco folks, in their infinite wisdom, insist on calling a "star"). According to a Bell Laboratories engineer named Ralph Carlsen, the octothorpe and asterisk keys were developed in the early 1960s and originally intended to be used only to access computer systems via a telephone line. The octothorpe symbol itself had already existed for many years, although it was usually called a "pound sign" or "number sign" because it was often used in commerce to designate weight or quantity.
According to Ralph Carlsen, a fellow Bell Labs engineer named Don MacPherson invented the term "octothorpe" when faced with the task of explaining the new touch-tone phones to corporate users. MacPherson chose "octo" (Latin for "eight") because there were eight points on the symbol.
"Thorpe" is indeed an Old Norse word meaning "village," often found in the names of English towns, but that was evidently not the source in this case. According to Carlsen, "thorpe" was chosen because at the time MacPherson was involved in a campaign pressing for the return of legendary athlete Jim Thorpe's Olympic medals from Sweden..
Word Detective (http://www.word-detective.com/072999.html#octothorpe [accessed 20090708]
[PJC]
octothorp
Otherwise known as the numeral sign. It has also been used as
a symbol for the pound avoirdupois, but this usage is now
archaic. In cartography, it is also a symbol for village: eight
fields around a central square, and this is the source of its
name. Octothorp means eight fields.
Robert Bringhurst (The Elements of Typographic Style (2d edition, 1996), Hartley & Marks, Publishers, Point Roberts, WA; Vancouver, BC, Canada, p. 282)
[Joel Neely]