Liquidity refers to buying and selling activity for a particular asset. When a market is illiquid, it means there are few buyers and sellers transacting. Some crypto assets are more liquid than others. For example, the Binance Bitcoin marketplace is one of the most liquid bitcoin markets in the world, whereas the market for a rare altcoin or NFT with few buyers and sellers is very illiquid.
NFT Term
Illiquid
Definition of Illiquid from the NFTguild.com glossary.

