Emily Dickinson Lexicon

THEME, n. [L. thema; Gr. θεμα, from τιθημι, to set or place.]

1. A subject or topic on which a person writes or speaks. The preacher takes a text for the theme of his discourse. When a soldier was the theme, my name / Was not far off. Shak.
2. A short dissertation composed by a student. Milton.
3. In grammar, a radical verb, or the verb in its primary absolute sense, not modified by inflections; as, the infinitive mode in English. But a large portion of the words called themes in Greek, are not the radical words, but are themselves derivative forms of the verb. The fact is the same in other languages.
4. In music, a series of notes selected as the text or subject of a new composition.