The spelling of the word "MEBETACD" is based on the International Phonetic Alphabet (IPA) transcription, which uses phonetic symbols to represent the sounds of speech. The letters "M-E-B-E-T-A-C-D" correspond to the following IPA symbols: /m/ for the first sound, /ɛ/ for the second, /b/ for the third, /ɛ/ for the fourth, /t/ for the fifth, /a/ for the sixth, /k/ for the seventh, and /d/ for the eighth. Together, these sounds create the unique phonetic pattern of the word "MEBETACD."