NOUN (2)

1. the mistress of a chateau or large country house;

2. a chain formerly worn at the waist by women; for carrying a purse or bunch of keys etc.;

The Collaborative International Dictionary of English v.0.48:

Chatelaine \Chat"e*laine\, n. [F. ch[^a]telaine the wife of a
   castellan, the mistress of a chateau, a chatelaine chain.]
   An ornamental hook, or brooch worn by a lady at her waist,
   and having a short chain or chains attached for a watch,
   keys, trinkets, etc. Also used adjectively; as, a chatelaine
   chain.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chatelaine
    n 1: the mistress of a chateau or large country house
    2: a chain formerly worn at the waist by women; for carrying a
       purse or bunch of keys etc.