Theme

Part of speech: noun (n.)

1. A subject or topic on which a person writes or speaks; a proposition for discussion or argument; a text. My theme is alway one and ever was. Chaucer. And when a soldier was the theme, my name Was not far off. Shak.

2. Discourse on a certain subject. Then ran repentance and rehearsed his theme. Piers Plowman. It was the subject of my theme. Shak.

3. A composition or essay required of a pupil. Locke.

4. A noun or verb, not modified by inflections; also, that part of a noun or verb which remains unchanged (except by euphonic variations) in declension or conjugation; stem.

5. That by means of which a thing is done; means; instrument. [Obs.] Swift.

6. The leading subject of a composition or a movement.