Dirt, Soil, Earth
noun
The kanji and the word are exactly the same. That means they share meanings as well. 土 generally refers to dirt or soil or earth.
つち
Since this word is made up of a single kanji, it uses the kun'yomi reading. Here's a mnemonic to help you to remember it: You look through the soil. You're trying to find something. As you dig and sift, you come across not one but two cheeses (つち). Pull them out of the ground and put them in your mouth. How do the two cheeses taste and compare?
そのトマト、土がついてるよ。
That tomato has some dirt on it.
これはふじ山の土なんだよ。
This is soil from Mt. Fuji.
モグラが土に入っていった。
The mole was going into the ground.