hole
An empty space or opening in something solid.
A hole is an empty space in something solid, like an opening that goes through or into an object. You might poke a hole in paper with a pencil, dig a hole in your backyard for planting a tree, or notice a hole in your sock where your toe pokes through.
Holes appear everywhere in daily life. A doughnut has a hole in its middle. Swiss cheese is famous for its holes. Your nose has two holes called nostrils that let you breathe. When you lose a tooth, you feel the hole with your tongue until the new tooth grows in.
Some holes are useful and intentional: the holes in a colander drain water from pasta, the hole at the top of a pen cap helps prevent choking if someone accidentally swallows it, and the holes in your shoes let you thread the laces through. Other holes are problems: a hole in your bicycle tire means you need a patch, and a hole in the ozone layer worried scientists because it let in harmful radiation.
In golf, each section of the course is called a hole because players aim to hit their ball into a small hole in the ground. When someone completes all 18 sections, they've played 18 holes.
People use hole in expressions too. “Digging yourself into a hole” means making a bad situation worse, like when you keep lying to cover up an earlier lie.