The word "gammill" is spelled with a double "m" and a double "l" to indicate the pronunciation of the sound /mɪl/. This sound is made by closing your lips together (to make the /m/ sound) and then opening them slightly to create the /ɪ/ sound before closing them again to create the /l/ sound. The repeated letters help to emphasize the distinct sounds in this word. Overall, the spelling of "gammill" accurately represents its pronunciation in IPA phonetic transcription.