What does Boxing Day have to do with boxing?
"land bordering a large body of water," c.1300, from an Old English word or from Middle Low German schor "shore, coast, headland," or Middle Dutch scorre "land washed by the sea," all probably from Proto-Germanic *skur-o- "cut," from PIE *(s)ker- (1) "to cut" (see shear (v.)).
According to etymologists originally with a sense of "division" between land and water. But if the word began on the North Sea coast of the continent, it might as well have meant originally "land 'cut off' from the mainland by tidal marshes" (cf. Old Norse skerg "an isolated rock in the sea," related to sker "to cut, shear"). Old English words for "coast, shore" were strand (n.), waroþ, ofer. Few Indo-European languages have such a single comprehensive word for "land bordering water" (Homer uses one word for sandy beaches, another for rocky headlands). General application to "country near a seacoast" is attested from 1610s.
mid-14c., "to prop, support with a prop;" of obscure etymology though widespread in West Germanic; cf. Middle Dutch schooren "to prop up, support," Old Norse skorða (n.) "a piece of timber set up as a support." Related: Shored; shoring. Also as a noun, "post or beam for temporary support of something" (mid-15c.), especially an oblique timber to brace the side of a building or excavation.