What does Boxing Day have to do with boxing?
1825, "electrotype, stereotype," from French cliché, a technical word in printer's jargon for "stereotype block," noun use of past participle of clicher "to click" (18c.), supposedly echoic of the sound of a mold striking molten metal. Figurative extension to "trite phrase, worn-out expression" is first attested 1888, following the course of stereotype. Related: Cliched (1928).
A much used expression that has lost its freshness and descriptive power. Some clichés are “I thank you from the bottom of my heart” and “It's only a drop in the bucket.”