dirt
Loose earth or stuff that makes things dirty.
Dirt is loose soil or earth, the stuff that covers most of the ground outdoors. When you dig in your backyard, scoop up handfuls at a playground, or track muddy footprints inside after rain, you're dealing with dirt. It's made of tiny bits of rock, dead plants, minerals, and often living things like worms and microscopic organisms.
Dirt feels different depending on where you find it. Sandy dirt runs through your fingers like sugar. Clay dirt clumps together and can be shaped when wet. Rich garden dirt, full of decomposed leaves and other organic matter, feels soft and crumbly.
The word also means any substance that makes things unclean. Dirt on your clothes might be mud, dust, food stains, or grease. When something gets dirty, it picks up unwanted material that needs washing away. A dirt-cheap price is extremely low, so inexpensive it's almost like getting something for nothing.
Interestingly, dirt becomes soil when gardeners and farmers talk about it as a resource for growing things. The difference is mostly about respect: dirt is what you sweep up, while soil is what you nurture. But they're made of the same stuff, the loose earth beneath our feet that supports nearly all life on land.