"COSOST" is a non-existent word in the English language. The spelling of the word is not common nor does it have any phonetic roots. However, using the International Phonetic Alphabet (IPA), the word can be transcribed as /kəʊˈsɒst/. This transcription uses symbols to represent the pronunciation of each letter of the word. Apart from that, there is no known meaning or origin for the word "COSOST." When writing or using a word, it's essential to check its spelling and context to avoid confusion or misleading information.