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bi·con·cave .bī-(.)kän-'kāv, (')bī-'kän-. adj concave on both sides <\biconcave vertebrae> <a \biconcave lens>
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adj.
having a hollowed surface on both sides. Biconcave lenses are used to correct short-sightedness. Compare biconvex.
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bi·con·cave (bi″kon-kāvґ) [bi- + concave] having two concave surfaces, as the opposite sides of a structure.Medical dictionary. 2011.