"Kaa jinn" is a term that is unfamiliar to most people, as it does not exist in the English language. However, there are several similar words that one can use depending on the context. For instance, if you are referring to a genie or spirit in Islamic mythology, the synonyms could include "jinni", "djinni" or simply "jinn". Also, if you are talking about a snake species, you could use synonyms like "cobra" or "aspidelaps scutatus". In summary, the choice of synonym depends on the intended meaning of the term "kaa jinn".