The word "OPACA" is spelled with five letters and pronounced as /əʊˈpækə/. In phonetic transcription, the first two letters "o" and "p" are pronounced as a diphthong /əʊ/, followed by the consonant sound /p/ represented by the letter "p". The next two letters "a" and "c" are pronounced as separate vowels /ə/ and /æ/ respectively, and the final letter "a" is pronounced as a schwa sound /ə/. The spelling of OPACA reflects the Italian origins of the word, meaning "opaque."