The Collaborative International Dictionary of English v.0.48:

Lady \La"dy\, a.
   Belonging or becoming to a lady; ladylike.
   [1913 Webster] "Some lady trifles."            --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lady \La"dy\ (l[=a]"d[y^]), n.; pl. Ladies (l[=a]"d[i^]z).
   [OE. ladi, l[ae]fdi, AS. hl[=ae]fdige, hl[=ae]fdie; AS.
   hl[=a]f loaf + a root of uncertain origin, possibly akin to
   E. dairy. See Loaf, and cf. Lord.]
   [1913 Webster]
   1. A woman who looks after the domestic affairs of a family;
      a mistress; the female head of a household.
      [1913 Webster]

            Agar, the handmaiden of Sara, whence comest thou,
            and whither goest thou? The which answered, Fro the
            face of Sara my lady.                 --Wyclif (Gen.
                                                  xvi. 8.).
      [1913 Webster]

   2. A woman having proprietary rights or authority; mistress;
      -- a feminine correlative of lord. "Lord or lady of high
      degree." --Lowell.
      [1913 Webster]

            Of all these bounds, even from this line to this, .
            . .
            We make thee lady.                    --Shak.
      [1913 Webster]

   3. A woman to whom the particular homage of a knight was
      paid; a woman to whom one is devoted or bound; a
      sweetheart.
      [1913 Webster]

            The soldier here his wasted store supplies,
            And takes new valor from his lady's eyes. --Waller.
      [1913 Webster]

   4. A woman of social distinction or position. In England, a
      title prefixed to the name of any woman whose husband is
      not of lower rank than a baron, or whose father was a
      nobleman not lower than an earl. The wife of a baronet or
      knight has the title of Lady by courtesy, but not by
      right.
      [1913 Webster]

   5. A woman of refined or gentle manners; a well-bred woman;
      -- the feminine correlative of gentleman.
      [1913 Webster]

   6. A wife; -- not now in approved usage. --Goldsmith.
      [1913 Webster]

   7. Hence: Any woman; as, a lounge for ladies; a cleaning
      lady; also used in combination; as, saleslady.
      [PJC]

   8. (Zool.) The triturating apparatus in the stomach of a
      lobster; -- so called from a fancied resemblance to a
      seated female figure. It consists of calcareous plates.
      [1913 Webster]

   Ladies' man, a man who affects the society of ladies.

   Lady altar, an altar in a lady chapel. --Shipley.

   Lady chapel, a chapel dedicated to the Virgin Mary.

   Lady court, the court of a lady of the manor.

   Lady crab (Zool.), a handsomely spotted swimming crab
      (Platyonichus ocellatus) very common on the sandy shores
      of the Atlantic coast of the United States.

   Lady fern. (Bot.) See Female fern, under Female, and
      Illust. of Fern.

   Lady in waiting, a lady of the queen's household, appointed
      to wait upon or attend the queen.

   Lady Mass, a Mass said in honor of the Virgin Mary.
      --Shipley.

   Lady of the manor, a lady having jurisdiction of a manor;
      also, the wife of a manor lord.

   Lady's maid, a maidservant who dresses and waits upon a
      lady. --Thackeray.

   Our Lady, the Virgin Mary.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lady
    n 1: a polite name for any woman; "a nice lady at the library
         helped me"
    2: a woman of refinement; "a chauffeur opened the door of the
       limousine for the grand lady" [syn: dame, madam, ma'am,
       lady, gentlewoman]
    3: a woman of the peerage in Britain [syn: Lady, noblewoman,
       peeress] [ant: Lord, noble, nobleman]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "Lady":
   Eminence, Grace, Her Excellency, Her Highness, Her Ladyship,
   Her Majesty, Highness, His Lordship, His Majesty, Honor,
   Imperial Highness, Imperial Majesty, Ladyship, Lord, Lordship,
   Majesty, My Lady, My Lord, Reverence, Royal Highness,
   Royal Majesty, Serene Highness, Worship, Your Lordship, milady,
   milord



Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "lady":
   Dulcinea, Eve, Frau, Fraulein, Miss, Mistress, Mlle, Mme, Mmes,
   acceptable person, archduchess, baroness, best girl, better half,
   capital fellow, common-law wife, concubine, countess, dame,
   daughter of Eve, diamond, distaff, domina, dona, donna, dowager,
   dream girl, duchess, faithful, feme, feme covert, femme, frow,
   galantuomo, gem, gentilhomme, gentleman, gentlewoman, gill, girl,
   girl friend, good fellow, good lot, good man, good person,
   good sort, good woman, goodwife, goody, grand duchess, helpmate,
   helpmeet, honest man, honest woman, inamorata, jewel, jill, jo,
   khanum, lady love, lass, lassie, madam, madame, mademoiselle,
   man of honor, marchioness, margravine, married woman, matron,
   mem-sahib, mensch, mesdames, milady, mistress, noblewoman,
   old lady, old woman, pearl, peeress, perfect gentleman,
   perfect lady, persona grata, prince, real lady, real man, rib,
   right sort, rough diamond, senhora, senhorita, signora, signorina,
   squaw, straight shooter, true blue, truepenny, trusty, viscountess,
   vrouw, wahine, weaker vessel, wedded wife, wife, woman,
   woman of honor, worthy



The Free On-line Dictionary of Computing (30 December 2018):

LADY

    ["Key Concepts in the INCAS Multicomputer Project",
   J. Nehmer et al IEEE Trans Soft Eng SE-13(8):913-923 (Aug
   1987)].

   (1996-06-21)