Definition of "theme"

theme

/θiːm/

noun
plural themes
1. A subject, now especially of a talk or an artistic piece; a topic.
  Quotations
  "Had not you once a beautiful daughter, named Mary?" said the stranger."It is a heartrending question, man," said Andrew; "but certes, I had once a beloved daughter named Mary.""What became of her?" asked the stranger.Andrew shook his head, turned round, and began to move away; it was a theme that his heart could not brook.
  1828, James Hogg, Mary Burnet
2. A recurring idea; a motif.
  1. A concept with multiple instantiations.
  2. (graphical user interface) any of various skins for an app, affecting the visuals and perhaps other elements such as sound effects.
3. (dated) An essay written for school.
  Quotations
  Father Dolan came in today and pandied me because I was not writing my theme.
  1917, James Joyce, A Portrait of the Artist as a Young Man
  […] his themes and exercises were in constant demand for what we called cogging and American students rather grandly called plagiarization.
  1979, Tri-Quarterly, numbers 46-47, page 273
4. (music) The main melody of a piece of music, especially one that is the source of variations.
5. (film, television) A song, or a snippet of a song, that identifies a film, a TV program, a character, etc. by playing at the appropriate time.
6. (grammar) The stem of a word.
7. (linguistics) thematic relation of a noun phrase to a verb.
8. (linguistics) Theta role in generative grammar and government and binding theory.
9. (linguistics) Topic, what is generally being talked about, as opposed to rheme.
10. A regional unit of organisation in the Byzantine empire.
verb
third-person singular simple present themes, present participle theming, simple past and past participle themed
1. (transitive) To give a theme to.
2. (computing, transitive) To apply a theme to; to change the visual appearance and/or layout of (software).