What does Boxing Day have to do with boxing?
late 14c., from Old French deriver "to flow, pour out; derive, originate," from Latin derivare "to lead or draw off (a stream of water) from its source" (in Late Latin also "to derive"), from phrase de rivo (de "from" + rivus "stream;" see rivulet). Etymological sense is 1550s. Related: Derived; deriving.
derive de·rive (dĭ-rīv')
v. de·rived, de·riv·ing, de·rives
To obtain or receive from a source.
To produce or obtain a chemical compound from another substance by chemical reaction.