Bottomless means having no bottom, or seeming to have no bottom because it goes so deep you can't see or reach the end.

When you look down into a deep, dark well and can't see the bottom, it might feel bottomless even though it does eventually end somewhere far below. A bottomless pit sounds terrifying precisely because it suggests falling forever with nothing to catch you. In stories and myths, bottomless chasms and abysses represent the unknown and the infinite.

People also use bottomless to describe something that seems endless or inexhaustible. A restaurant advertising bottomless fries means you can keep ordering more without limit. When someone has a bottomless appetite for books, they always want to read another one. A bottomless supply of energy means someone never seems to tire out, no matter how long they work or play.

The word captures the feeling of encountering something so deep or abundant that you can't imagine reaching its end, whether that's a physical depth you're staring into or a seemingly endless resource.