theme

1. theme (noun) — sense 1

Definition: A subject, now especially of a talk or an artistic piece; a topic.

Example: "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.

2. theme (noun) — sense 2

Definition: A recurring idea; a motif.: A concept with multiple instantiations.

Example: variations on the theme of entrepreneurial resourcefulness

3. theme (noun) — sense 3

Definition: A recurring idea; a motif.: Any of various colors, or color palettes, in which a design is offered; (graphical user interface) any of various skins for an app, affecting the visuals and perhaps other elements such as sound effects.

Example: switch to a dark theme to conserve battery power

4. theme (verb) — sense 4

Definition: To give a theme to.

Example: We themed the birthday party around superheroes.

5. theme (verb) — sense 5

Definition: To apply a theme to; to change the visual appearance and/or layout of (software).