stand-up historian
n.— «The Great Squirrel Stampede of 1826 is one of David Heighway’s favorite tales. Caused by an overpopulation of squirrels that lost their food supply for natural reasons across the Midwest, it’s on the local historian’s A-list of material. That sort of stuff comes in handy during brief presentations, or as he refers to it, playing “stand-up historian.”» —“Hamilton County historian is interested in area’s unusual stories” by Chris Sikich Indianapolis Star (Indiana) May 28, 2008. (source: Double-Tongued Dictionary)
Further reading
If someone’s got melon, it means they’re smart. The expression most likely arose because of the resemblance between a melon and a human head. Several other foods are associated with having brains, including a cabbage, a gourd, and even a...