What does POCKET mean?

noun

1. a small pouch inside a garment for carrying small articles
2. an enclosed space“the trapped miners found a pocket of air”
3. a supply of money“they dipped into the taxpayers' pockets”
4. (bowling) the space between the headpin and the pins behind it on the right or left“the ball hit the pocket and gave him a perfect strike”
5. a hollow concave shape made by removing something
6. a local region of low pressure or descending air that causes a plane to lose height suddenly
7. a small isolated group of people“they were concentrated in pockets inside the city”
8. (anatomy) saclike structure in any of various animals (as a marsupial or gopher or pelican)