-ess

1.
a suffix forming distinctively feminine nouns:
countess; goddess; lioness.
Origin
Middle English -esse < Old French < Late Latin -issa < Greek
Usage note
Since at least the 14th century, English has both borrowed feminine nouns in -ess from French (-esse in French and in some early English forms) and applied the French ending to native or naturalized words, most frequently agent nouns in -er or -or. Some of the earliest borrowings—titles for the nobility and church dignitaries—are still in use, among them countess, princess, duchess, empress, abbess, and prioress. Of the scores of new nouns that were created from the 14th century on, many have long ago disappeared entirely from use: devouress; dwelleress. But many have survived, although their use has declined sharply.
Nouns in -ess denoting occupation or profession are rapidly disappearing from American English. Airlines now refer to cabin personnel as flight attendants, not stewards and stewardesses. In the arts, authoress, editress, poetess, sculptress, and similar terms are either rejected or discouraged and almost always replaced by author, editor, poet, sculptor. Nouns in -ess designating the holder of public office are hardly ever encountered in modern American usage. Women holding the office of ambassador, mayor, or governor are referred to by those titles rather than by the older, sex-marked ambassadress, mayoress, or governess. (Governess has developed a special sense in relation to childcare; this use is less common in the U.S. than in Britain.) Among other terms almost never used in modern American English are ancestress, directress, instructress, manageress, oratress, postmistress, and proprietress. If the sex of the performer is not relevant to performance of the task or function, the neutral term in -er or -or is now widely used.
Some nouns in -ess are still current: actress (but some women in the acting profession prefer to be called actors); adventuress; enchantress; heiress (largely in journalistic writing); hostess (but women who conduct radio and television programs are referred to as hosts); millionairess; murderess; seamstress; seductress; sorceress; temptress; and waitress (the substitute term server has not been widely adopted).
Jewess and Negress are usually considered offensive today. Mistress has given way to master in the sense of one who has acquired expertise in something: She is a master at interpreting financial reports. See also -enne, -ette, -trix.
British Dictionary definitions for -ess

-ess

suffix
1.
indicating a female: waitress, lioness
Usage note
The suffix -ess in such words as poetess, authoress is now almost invariably regarded as disparaging or extremely old-fashioned; a gender-neutral term poet, author is preferred
Word Origin
via Old French from Late Latin -issa, from Greek
Word Origin and History for -ess

fem. suffix, from French -esse, from Late Latin -issa, from Greek -issa (cognate with Old English fem. agent suffix -icge); rare in classical Greek but more common later, in diakonissa "deaconess" and other Church terms picked up by Latin.

Slang definitions & phrases for -ess

-ess

suffix
  1. used to form nouns A woman member of the indicated group or calling •A standard
  2. now used most often in slang partly because the standard use is regarded as, and sometimes meant to be, offensive: loaferess/ muggess/ veepess (1400s+)