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

Initialism of south. / Initialism of season (group of episodes of a series). / (usually clothing, singular only) Initialism of small (the manufactured size or an item of that size).

(usually clothing) Initialism of small (of the manufactured size).

(set theory) An axiomatic set theory, developed by logician George Boolos, in which several of the axioms of ZF are derivable as theorems.

(business, often attributive) Initialism of sales and administration.

plural of A+

plural of A*

plural of A*

Possessive marker, indicating that an object belongs to the noun or noun phrase bearing the marker. / In the absence of a specified object, used to indicate “the house/place/establishment of”.

(sometimes proscribed) Used to form the plurals of numerals, letters, some abbreviations and some nouns, usually because the omission of an apostrophe would make the meaning unclear or ambiguous.