The spelling of the word "fat neck" can be explained using IPA phonetic transcription. The word "fat" is pronounced as /fæt/ with a short "a" sound, while "neck" is pronounced as /nɛk/ with an "e" sound. The two words are then joined together with a glottal stop or a pause in between, resulting in the pronunciation of /fæt ˈnɛk/. This word is commonly used to describe a person with a thick or large neck, often due to excess weight or muscle mass.