himno

One word for both English words. A himno is a hymn in the religious sense, sung in praise of a god, and it is an anthem in the civic sense, sung in praise of a nation or a cause. Nacia himno is a national anthem, and it is the collocation you will meet most often. Himnaro is a hymnbook, with the -ar- suffix that makes a collection out of a unit.

For this movement the word has one obvious referent.La Espero is la himno: Zamenhof's 1890 poem set to Félicien Menu de Ménil's 1909 march, sung standing at the opening of every Universala Kongreso since the 1920s. The song lesson on this site has the full text, the translation and the recording. It is worth noticing what kind of anthem it is. It has no country, no flag, no monarch and no battle in it; the third verse's boast is a neŭtrala lingva fundamento and a family circle, which is a strange thing to march to and is exactly what the movement wanted.

The music does a lot of work, and the poetic Esperanto article covers the machinery: fixed penultimate stress means Esperanto scans on sight, and Rule 16 elision gives de l' homaro where the metre needs a syllable back. Anthems are where those conventions are most audible, because everybody in the hall has to land on the same beat.

Himno is not a general word for song. That is kanto, or kanzono for an art song. A himno praises something.