Squill was a type of plant native to Balancar.
It was commercially grown and used to make syrup of squill. A reputed drought on Balancar was in reality a plot devised by the planet's Agricultural Consortium to hoard it and drive up the prices. Quark successfully uncovered the plot and managed to procure a small shipment of the syrup by threatening the Consortium's chief accountant with exposure. (DS9: "The Magnificent Ferengi")