Definition of "s"

The nineteenth letter of the English alphabet, called ess and written in the Latin script.  examples

The ordinal number nineteenth, derived from this letter of the English alphabet, called ess and written in the Latin script.  examples

(metrology) Abbreviation of scruple. (unit of mass in the apothecaries' system)

(physics) Abbreviation of strange quark.  examples

Alternative form of s.  examples