Hymn appears to mean the most (6)
'hymn' is the definition.
'to mean the most' is the wordplay.
'ANTHEM' is hidden within the letters.
However, I am uncertain how the hidden word is indicated.
'appears' acts as a link.
Can you help me to learn more?
(Other definitions for anthem that I've seen before include "The man for a popular song", "National or religious song", "air of patriotism?", "One for doomed youth", "National or church song".)