The Collaborative International Dictionary of English v.0.48:

Courtesy \Courte"sy\ (k[^u]rt"s[y^]), n. [See the preceding
   word.]
   An act of civility, respect, or reverence, made by women,
   consisting of a slight depression or dropping of the body,
   with bending of the knees. [Written also curtsy and
   curtsey.]
   [1913 Webster]

         The lady drops a courtesy in token of obedience, and
         the ceremony proceeds as usual.          --Golgsmith.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

curtsey \curt"sey\, curtsy \curt"sy\(k[^u]rt"s[y^]), n.
   An act of civility, respect, or reverence, made by women,
   consisting of a slight depression or dropping of the body,
   with bending of the knees. Same as 2nd Courtesy, n..

   Syn: curtsy; courtesy.
        [1913 Webster + WordNet 1.5] curtsey

The Collaborative International Dictionary of English v.0.48:

curtsey \curtsey\, curtsy \curtsy\v. i.
   to perform a curtsy.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

curtsy
    n 1: bending the knees; a gesture of respect made by women [syn:
         curtsy, curtsey]
    v 1: bend the knees in a gesture of respectful greeting [syn:
         curtsy, curtsey]
    2: make a curtsy; usually done only by girls and women; as a
       sign of respect; "She curtsied when she shook the Queen's
       hand" [syn: curtsy, bob]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "curtsy":
   accost, address, bend, bend the knee, bend the neck, bend to,
   bending the knee, bid good day, bid good morning, bob,
   bob a curtsy, bob down, bow, bow and scrape, bow down,
   bow the head, bow to, bowing and scraping, cringe to, crouch,
   crouch before, dipping the colors, do homage, do obeisance, duck,
   embrace, exchange greetings, fall down before, genuflect,
   genuflection, greet, greeting, grovel, hail, hand-clasp, handshake,
   hello, homage, how-do-you-do, hug, inclination, kiss, kiss hands,
   kneel, kneel to, kneeling, knuckle to, kowtow, lift the hat,
   make a leg, make a reverence, make obeisance, making a leg, nod,
   nod to, obeisance, obsequiousness, presenting arms, prostration,
   pull the forelock, reverence, salaam, salutation, salute,
   say hello, scrape, servility, shake, shake hands, smile,
   smile of recognition, squat, standing at attention, stoop,
   submission, submissiveness, supination, touch the hat, truckle to,
   uncover, wave