Some boatman - the mariner in Land of the Free? (6)
I believe the answer is:
anthem
'land of the free?' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'some boatman the mariner' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'ANTHEM' is hidden in the letters of 'boatman the mariner'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for anthem that I've seen before include "Song of praise or loyalty" , "Song in praise of a nation" , "National or religious song" , "National or church song" , "One for doomed youth" .)