chalk talk
n.— «In recent weeks, Swann has been lining up paid speaking engagements—”chalk talks,” as he calls them—with local and national corporations.» —“NFL alums look to boost profiles” by Scott Wong Arizona Republic (Phoenix) Nov. 23, 2007. (source: Double-Tongued Dictionary)
Further reading
juicy noun. A person who illicitly carries alcohol in a water bottle. «Gwen Alexander, who’s been working at the Astoria pool for two years, confirms there haven’t been any issues with fighting this year but she said rule enforcement is...
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I feel that this term has been used since at least the 1950’s to mean either a lecture or a presentation, probably on a mathematical or technical subject.
announcements written in chalk on sidewalks. Placed where there is a lot of foot traffic. My first encounter with this was at a college campus twenty years ago. Not used as much these days.
I know this term as a form of storytelling, illustrated by simple line drawings (often on a blackboard) as the story is told. See, for example: the Chalk Talk Manual by Harlan Tarbell (Dennison, 1962) and , more recently, Chalk Talk Stories, by Arden Druce (Scarecrow Press, 1993).