waist

Definitions

General English

Construction

  • The narrowest section of a column or similar building element.

Medical

  • noun the narrow part of the body below the chest and above the buttocks

Origin & History of “waist”

Waist is something of a mystery word, but it is generally taken to denote etymologically ‘girth to which one has grown’. It is probably descended from an unrecorded Old English *wæst, which would have gone back to prehistoric Germanic *wakhs- ‘grow’, source of English wax ‘grow’ (as in wax and wane). Related forms which support this hypothesis include Icelandic vöxstr and Gothic wahstus, which mean ‘growth, size’.
http://www.dictionarycentral.com/definition/waist.html