theme

ot noun

1. A subject of a talk or an artistic piece; a topic.
2. A recurring idea; a motif.
3. An essay written for school.
4. The main melody of a piece of music, especially one that is the source of variations.

fe’l verb

1. To give a theme to. We themed the birthday party around superheroes.
2. To apply a theme to; to change the visual appearance and/or layout of (software).