A shitcoin is any system that is not cryptodynamically secure yet purports to capture the value proposition of Bitcoin.

Shitcoins are presumed to be scams, though it remains possible for proponents be to well-intentioned yet ignorant of cryptodynamic principles. By way of example, proof-of-stake technologies are shitcoins.

While there may be implementations of Bitcoin that are more secure than others, these are matters of degree. No Bitcoin can be shown to be absolutely secure. As such the term is not reasonably applied to any Bitcoin. By way of example, proof-of-memory technologies may not be shitcoins (despite failure to achieve central objectives).