Infertile describes soil that cannot grow healthy plants, or a person or animal whose body cannot produce offspring.

When farmers call land infertile, they mean the soil lacks the nutrients plants need to thrive. Desert sand is infertile because it contains almost no organic matter or minerals. After years of growing the same crops, even good farmland can become infertile if nutrients aren't replaced through fertilizer or crop rotation. The opposite is fertile soil, which is rich and productive.

The word also describes people or animals who cannot have biological children, though doctors and scientists more often use the technical term infertility when discussing this medical condition. Many factors can cause infertility, and it affects millions of people. Modern medicine offers various treatments and options. Many people who experience infertility build families through adoption or other paths to parenthood.

You might also hear infertile used metaphorically to describe situations where nothing productive happens, like calling a brainstorming session infertile if it produces no good ideas. But the literal meanings relating to soil and reproduction are the most common uses you'll encounter.