A memecoin is a type of cryptocurrency whose value is based on hype, community enthusiasm, and viral attention rather than on any product, service, cash flow, or distinctive technology. The category is named for the internet memes many of these tokens are built around, often a mascot, a joke, or a personality. Like other digital assets, a memecoin is recorded on a blockchain and treated as property for United States tax purposes. What sets it apart from a cryptocurrency such as bitcoin or ether is the absence of even a claimed utility: the token exists to be traded, and its price is a direct function of how many people are paying attention and willing to buy.
The practical consequence is that a memecoin is closer to a speculative bet on crowd behavior than to an investment in an asset with any independent basis of value. That is a factual description of how the instrument works, not a judgment about anyone who buys one, but it is the fact that most determines what can happen to the money put into it.