lenticular

The adjective lenticular describes things with a round shape that's thinner on the edges and widest in the middle, like a lentil. A classic flying saucer is also lenticular.

Lenticular is sometimes defined as "lens-shaped," and its Latin root is lens, "lentil." A double-convex lens is shaped like a lentil (imagine two spoons facing each other to get the idea). Lenticular can describe that particular shape, like a lenticular cloud formation. It can also mean "relating to a lens," so eye doctors diagnose conditions like lenticular astigmatism, which affects the eye's lens and causes blurred vision.