The spelling of the word "bells cat" can be explained using the International Phonetic Alphabet (IPA). "Bells" is pronounced as /bɛlz/ with the "e" pronounced as "eh" and the "s" at the end pronounced as "z". "Cat" is pronounced as /kæt/ with the "a" pronounced as "ah" and the "t" at the end pronounced as "t". Together, the word is pronounced as /bɛlz kæt/. It is important to use correct spelling and pronunciation to effectively communicate in any language.
The term "bells cat" does not have an established etymology as it does not correspond to any known phrase or word. It seems to be a combination of the words "bells" and "cat", but there is no clear indication of its origin or meaning. It is possible that it is an invented or personal expression with no widely recognized etymology.