S

S is the nineteenth letter in the modern Latin alphabet.

Semitic Šîn (bow) was pronounced as /S/ as the modern English digraph SH. In Greek, there was only one phoneme /s/ and no /S/, so Greek σιγμα (sigma) came to represent the Greek /s/ phoneme. The name "sigma" probably comes from the Semitic letter "Sâmek" and not "Šîn". In Etruscan and Latin, the /s/ value was maintained, and only in modern languages, S came to represent other sounds, like /S/ in Hungarian or /z/ in English, French and German (in English rise; in French lisez, "read! (imperative pl.)"; in German lesen "to read").

An archaic alternative form of s, ſ, called the long s or medial s, was used at the beginning or in the middle of the word; the modern form, the short or terminal s, was used at the end of the word. The ligature of ſs became the German ess-tsett ( ß ).

Sierra represents the letter S in the NATO phonetic alphabet.

Meanings for S

In biochemistry, S is the symbol for serine.
In calendars, S is often the abbreviation for Saturday or Sunday, or the month September. When it is necessary to disambiguate, U is sometimes used for "Sunday" to avoid confusing it with "Saturday".
In chemistry, S is the symbol for sulfur.
In computing, <s> is the HTML tag to create strike-through text.
In education, S is a satisfactory grade.
In financial securities, S is the stock symbol for Sears, Roebuck and Co.
In international licence plate codes, S stands for Sweden.
In mathematics, blackboard bold represents the sedenions.
In the Metric system,
- S is the symbol for siemens, the SI derived unit for electric conductance.
- s is the symbol for the second, the SI base unit for time.
In physics, S is the symbol for the unit Svedberg.