It occurred to me I had no idea as to its etymology.
"Mr George has been so excited, that he finds it necessary to wipe his forehead on his shirt-sleeve. Even while he whistles his impetuosity away with the National Anthem, some involuntary shakings of his head and heavings of his chest still linger behind; not to mention an occasional hasty adjustment with both hands of his open shirt-collar, as if it were scarcely open enough to prevent his being troubled by a choking sensation. In short, Allan Woodcourt has not much doubt about the going down of Mr Tulkinghorn on the field referred to."

anthem
composition (in prose or verse) sung antiphonally," from L.L. antefana, from Gk. antiphona "verse response" (see antiphon). Sense evolved to "a composition set to sacred music" (c.1386), then "song of praise or gladness" (1591). Used in ref. to the English national song (technically a hymn) and extended to those of other nations.