Origin: bef. 900; ME
womman, wimman, OE
wīfman, equiv. to
wīf female +
man human being;
see wife, man 1 
Related forms: wom⋅an⋅less, adjective
Synonyms:
Woman, female, lady are nouns referring to adult human beings who are biologically female; that is, capable of bearing offspring. Woman is the general term. It is neutral, lacking either favorable or unfavorable implication, and is the most commonly used of the three: a wealthy woman; a woman of strong character, of unbridled appetites. In scientific, statistical, and other objective use, female is the neutral contrastive term to male and may apply to plants and animals also: 104 females to every 100 males; Among lions, the female is the chief hunter. Female is sometimes used in disparaging contexts: a gossipy female; a conniving female. Lady meaning “refined, polite woman” is a term of approval or praise: a real lady in all things; to behave like a lady.
Usage note:2. Although formerly
woman was sometimes regarded as demeaning and
lady was the term of courtesy,
woman is the designation preferred by most modern female adults:
League of Women Voters; American Association of University Women. Woman is the standard feminine parallel to
man. As a modifier of a plural noun,
woman, like
man, is exceptional in that the plural form
women is used:
women athletes; women students. The use of
lady as a term of courtesy has diminished somewhat in recent years (
the lady of the house), although it still survives in a few set phrases (
ladies' room; Ladies' Day).
Lady is also used, but decreasingly, as a term of reference for women engaged in occupations considered by some to be menial or routine:
cleaning lady; saleslady. See also girl, lady, -woman.