What does Boxing Day have to do with boxing?
"pertaining to the head," early 15c., from Latin cephalicus, from Greek kephalikos "pertaining to the head," from kephale (see cephalo-).
procephalic pro·ce·phal·ic (prō'sə-fāl'ĭk)adj. Relating to or located on or near the front of the head.
cephalic ce·phal·ic (sə-fāl'ĭk)adj.
Of or relating to the head.
Located on, in, or near the head.