* A surname: "Cai" is a common Chinese surname.
* Part of a Chinese name: "Cai" can be a component of a Chinese given name.
* A transliteration: It might be a transliteration of a word or name from another language.
To understand the meaning of "Cai" in a specific context, you need more information. For example:
* Is it part of a person's name? If so, you could look up the meaning of the name in a Chinese name dictionary.
* Is it used in a specific context? For example, is it a company name, a place name, or part of a phrase? This context could provide clues about its meaning.
Without further context, it's impossible to know what "Cai" means in English.