anthemyoudaoicibaDictYouDict[anthem 词源字典]
anthem: [OE] Anthem is ultimately an alteration of antiphon ‘scriptural verse said or sung as a response’ (which was independently reborrowed into English from ecclesiastical Latin in the 15th century). It comes from Greek antíphōnos ‘responsive’, a compound formed from anti- ‘against’ and phōné ‘sound’ (source of English phonetic, telephone, etc).

By the time it had become established in Old English, antiphon had already developed to antefn, and gradually the /v/ sound of the f became assimilated to the following n, producing antemne and eventually antem. The spelling with th begins to appear in the 15th century, perhaps influenced by Old French anthaine; it gradually altered the pronunciation.

The meaning ‘antiphon’ died out in the 18th century, having been succeeded by ‘piece of choral church music’ and more generally ‘song of praise’. The specific application to a ‘national song’ began in the 19th century.
=> antiphon, phonetic, telephone[anthem etymology, anthem origin, 英语词源]
anthem (n.)youdaoicibaDictYouDict
Old English ontemn, antefn, "a composition (in prose or verse) sung antiphonally," from Late Latin antefana, from Greek antiphona "verse response" (see antiphon). Sense evolved to "a composition set to sacred music" (late 14c.), then "song of praise or gladness" (1590s). Used in reference to the English national song (technically, as OED points out, a hymn) and extended to those of other nations. Modern spelling is from late 16c., perhaps an attempt to make the word look more Greek.