endosperm means in slang: 1. The theory that all sperm will be extinct 1. Food storage in the monocot (in Slang Dictionary, added by Wendy Brock)

What else does endosperm mean?

Starch granules found in grains embedded in gluten-forming protein from which flour is made or meal; between 80 and 85 percent of wheat kernels is endosperm. (in Cooking Dictionary)

It is the nutritive tissue found in seeds of flowering plants that surrounds and absorbs embryos. (in Merlin Dictionary)