"Biconcave" is a word in ENGLISH

A conical calcareous fossil, tapering to a point at the lower extremity, with a conical cavity at the other end, …

An upward concavity in the under side of a beam, girder, or lintel; also, a slight upward concavity in a …

Concave or hollow on both sides; double concave.

Specifically, having such a combination of concave and convex sides as makes the focal axis the shortest line between them. …

Concave on one side and convex on the other, as an eggshell or a crescent.

Convex on one side, and concave on the other. The curves of the convex and concave sides may be alike …

Concave on the upper side; -- said of a leaf whose disk is lower than the border.

A curve traced by a point in the circumference of a circle which rolls on the concave side in the …

A curve, traced by a point in the radius, or radius produced, of a circle which rolls upon the concave …

A lens convex on one side and concave on the other.

n. 1. the palate. 2. the concave side of a pot, jar. etc.

Obovate, with a concavity in each side, like the body of a violin; fiddle-shaped; as, a panduriform leaf; panduriform color …

Plane or flat on one side, and concave on the other; as, a plano-concave lens. See Lens.

sakbang a across, on the opposite side. Ang naglingkud sak-bang nákù, The one sitting across from me. v {1} [C] …

Three sided, the sides being plane or concave; having three salient angles or edges; trigonal.