biconcave

They were biconcave discs, the centers depressed on each side.

Parasitized red blood cells often lose their biconcave shape.

The aggregation of red blood cells progresses in the same manner except that cells are biconcave rather than spherical.

The resulting two biconcave elements are closer together than in the Dialyte/Celor design.

The sweets are hard, biconcave disc-shaped sweets, similar to the Fizzers product from the same company but without their fizziness.

Unstressed, normal human red blood cells are biconcave disc with a long axis of approximately 8 μm and a thickness of 2 μm.