"Christmas," 1551,
X'temmas, wherein the
X is an abbreviation for
Christ in
Christmas, from first letter of Gk.
Christos "Christ" (see
Christ). The earlier way to abbreviate it was
Xp- or
Xr-, corresponding to "Chr-," and the form
Xres mæsse for "Christmas" appears in the "Anglo-Saxon Chronicle" (c.1100).