There isn't actually a real word "masic," but let’s say it were pronounced /ˈmeɪsɪk/. In this case, the "m" would be spelled with an "m" because it's a bilabial nasal consonant, made by closing the lips and letting air flow out through the nose. The "a" would be spelled with an "a" because it's a short vowel pronounced near the front of the mouth. The "s" would be spelled with an "s" because it's a voiceless alveolar fricative sound, made by forcing air through a narrow space between the teeth and tongue. The "i" would be spelled with an "i" because it's a short vowel pronounced in the middle of the mouth. The final "c" would be spelled with a "c" because it's another voiceless alveolar fricative sound.