What does Boxing Day have to do with boxing?
early 15c., "to inspect and remove refuse from (spices)," from Anglo-French garbeler "to sift" (late 14c.), from Medieval Latin and Italian garbellare, from Arabic gharbala "to sift and select spices," related to kirbal "sieve," perhaps from Late Latin cribellum, diminutive of Latin cribrum "sieve" (see crisis). Apparently a widespread word among Mediterranean traders (cf. Italian garbellare, Spanish garbillo); sense of "mix up, confuse, distort language" (by selecting some things and omitting others) first recorded 1680s. Related: Garbled; garbling.