Anonymity is when something is not known or named.
Anonymous is when something is of unknown authorship or origin: someone who is not named, identified, or known. Their anonymity can be due to the fact that they want to remain anonymous. They lack individuality, distinction, or recognizability.
Anonymity has been one of the primary appeals of cryptocurrencies throughout their history. One such anonymity oriented technology is found in Zcash, which has implemented a cryptographic tool known as zero-knowledge proof and can grant any participant an option to shield their transactions, which allows them to transact without the need to reveal their addresses. It also obfuscates the transaction amount — this is a good example of anonymity in cryptocurrency.