Chatelaine definition is – the wife of a castellan : the mistress of a château. … she certainly needed keys. In the 18th century, the word chatelaine (borrowed from the French châtelaine) took on an additional meaning in English that alluded to this: the word came to be used for a decorative clasp or hook from which chains holding a watch …

: https://www.merriam-webster.com/dictionary/chatelaine