Symbol

A symbol is a drawing, shape, or object that stands for something else. It may be an aesthetic device, or a sign used to convey information, thus saving time, eliminating language barriers, or overcoming illiteracy. Symbols are used in cartography, for instance, to communicate geographical information.

The three categories of cartographic symbol shapes. By Sfitch

The asterisk derives from the two thousand year old character called the asteriskos, ※, used when proofreading poetry to mark lines that were duplicated. The asterisk evolved in shape over time, but its meaning as a symbol used to correct defects remained.

The "at-sign," @, has a surprisingly long history. It has been found on documents as far back as 1345,, where it appeared in a Bulgarian translation of a Greek chronicle. Originally, it wasn't used for email addresses! Instead, merchants used it in documents to represent a unit of measure for wine – the amphora (equivalent to about 1/13th of a barrel). This symbol likely stemmed from the Latin word "amphora," which referred to the large clay jars used to store wine. In a mercantile document sent by Florentine Francesco Lapi from Seville to Rome on May 4, 1536, @ was used to denote an amphora  of wine.

The nabla is a triangular symbol like an inverted Greek delta, which in math and physics, indicates a gradient or slope. Irish mathematician William Rowan Hamilton introduced the symbol in 1837, and Scottish mathematician Peter Guthrie Tait named it nabla because its downward-pointing triangle shape resembles a type of ancient harp with a similar name.

Nabla

The ampersand (&) was  regarded as the 27th letter of the English alphabet, as taught to children in the US and elsewhere. It was seen as a ligature of the letters 'e' and 't' to form the Latin word 'et' meaning 'and'. So the alphabet would go X,Y,Z and And. An example may be seen in M. B. Moore's 1863 book The Dixie Primer, for the Little Folks. To distinguish it from the rest, children started to say 'and per say and' which later evolved into 'ampersand'. 

The 'Swastika' was a symbol of well-being and harmony used by Buddhists, Hindus, and Jains until the Nazis decided to culturally appropriated it to an Aryan symbol to boost a sense of ancient lineage for the Germanic people.

In Hungarian, the @ symbol is called a kukac, which means "little worm" or "maggot."

In German slang, the @ symbol is called a klammeraffe or "spider monkey."

Robert Recorde invented the symbol '=' in 1557 to avoid having to write "is equal to" over and over again.

The pound symbol (£) is an L and is actually short hand for “Libra” - The basic unit of weight in the Roman Empire.

The world's oldest known smiley was on a 1635 Slovakian document, indicating the writer's happiness with the state of the Chamberlain of Trenčín's financial records.

By Breathe Icon Team. Wikipedia

The inventor of the modern smiley face symbol, Harvey Ball (1921-2001), was paid just $45 for the design. The American artist behind the now-ubiquitous smiley face spent just ten minutes on the design and did not copyright his creation. After Harvey Ball's death, his son Charlie said: "He left this world with no apologies and no regrets, happy to have this as his legacy."

The @ symbol was chosen for the first electronic mail because the developer, computer scientist Ray Tomlinson, "was mostly looking for a symbol that wasn’t used much."

In addition to the Percent sign (%) for 1/100, there is also a Per-mille symbol (‰) for 1/1,000 and a. per-the-thousand symbol called a Bias Point (‱) for 1/10,000.