secondhand book fair; used book market
Refers to an event or market where used books are sold, often held outdoors or in a community space.
週末に公園で古本市が開かれる。
A secondhand book fair is held in the park on weekends.
古本市で珍しい本を見つけた。
I found a rare book at the used book market.
Compound of 古本 (ふるほん, 'secondhand book') and 市 (いち, 'market' or 'fair').