What is the X in X-mas?
1828, from Mexican Spanish estampida, from Spanish, "an uproar," from estamper "to stamp, press, pound," from the same Germanic root that yielded English stamp (v.). The political sense is first recorded 1846. As the name of an annual exhibition of cowboy skills in Calgary, Alberta, Canada, it is attested from 1912.
1823; see stampede (n.). Related: Stampeded; stampeding.