n. A subject of a talk or an artistic piece; a topic.n. A recurring idea; a motif.n. The main melody of a piece of music, especially one that is the source of variations.n. The collection of color schemes, sounds, artwork etc., that "skin" an environment towards a particular motif.n. The stem of a wordn. thematic relation of a noun phrase to a verbn. Theta role in generative grammar and government and binding theory.n. Topic, what is being talked about, as opposed to rhemen. A regional unit of organisation in the Byzantine empire.v. To apply a theme to; to change the visual appearance and/or layout of (software).