What does Boxing Day have to do with boxing?
late 14c., "act of expelling contents of the stomach through the mouth," from Latin vomitare "to vomit often," frequentative of vomere "spew forth, discharge," from PIE root *wem- "to spit, vomit" (cf. Greek emein "to vomit," emetikos "provoking sickness;" Sanskrit vamati "he vomits;" Avestan vam- "to spit;" Lithuanian vemiu "to vomit," Old Norse væma "seasickness"). In reference to the matter so ejected, it is attested from late 14c.
early 15c.; see vomit (n.). Related: Vomited; vomiting.
vomit vom·it (vŏm'ĭt)
v. vom·it·ed, vom·it·ing, vom·its
To eject part or all of the stomach contents through the mouth, usually in a series of involuntary spasmic movements. n.
The act or an instance of ejecting matter from the stomach through the mouth.
Matter ejected from the stomach through the mouth.