* Bisect: To divide into two equal parts.
* Bisector: A line or plane that divides something into two equal parts.
* Bisexual: Attracted to both men and women.
* Biscuit: A small, flat, baked bread, often sweet.
* Bicycle: A vehicle with two wheels that is propelled by pedals.
* Biconcave: Concave on both sides, like a lens.
* Biconvex: Convex on both sides, like a lens.
* Binoculars: A device with two lenses that magnifies distant objects.
* Bishopric: The office or jurisdiction of a bishop.
* Bisque: A type of ceramic glaze that is typically white and opaque.
* Bisque: A rich, creamy soup, often made with seafood.
* Bistro: A small, informal restaurant, typically French.
* Bismuth: A heavy, brittle metal, sometimes used in medicine.
* Bisyllabic: Consisting of two syllables.
* Bittersweet: Having both pleasant and unpleasant qualities.
* Bivouac: A temporary camp, especially one made in the open.
This is not an exhaustive list, but it includes some common words that start with the prefix "bis".