noun. That branch of logic or rhetoric which treats of topics in the sense of topic, n.

noun. The most general, fundamental, and naturally elementary branch of geometry, which neither considers lengths, areas, or volumes in their character of being measurable, nor distinguishes straight from curved or crooked lines, nor plane from curved or bent surfaces, but studies only the manner in which the parts of places are continuously connected.

noun. Plural form of topic.

"Promoted to Headline (H2) on 7/30/08: An Aging Radical on Race and Politics yahooBuzzArticleHeadline = 'An Aging Radical on Race and Politics'; yahooBuzzArticleSummary = 'Article: A frank look at the title topics from a personal perspective -- with thoughts on current problems facing humanity (ranging from war, the environment, poverty and the prison-industrial complex)."

Tropics  tropics