Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

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.