Essence, essential nature.

Suffix appended to words to make a female form.

Used to form nouns from adjectives.

The name of the Latin-script letter S. / Something shaped like the letter S. (See esses)

To move in a changing direction, forming the shape of a letter S.

(software, IBM) Initialism of Enterprise Storage Server.

(evolutionary theory) evolutionarily stable strategy / (electronics) Initialism of electronic switching system. / (electrical) Abbreviation of energy storage system.

in being, in actuality, having actual existence (contradistinguished by in posse; compare in potentia)

Abbreviation of Essex.

simple past tense and past participle of ess