The word "Bathbun" is spelled as /bæθ bʌn/. This means that the first syllable is pronounced with a short 'a' sound and a voiced 'th' sound, while the second syllable is pronounced with a short 'u' sound and an 'n' sound. The spelling of the word represents its pronunciation, with the 'th' rather than 't' indicating the voiceless sound, and the 'u' rather than 'o' indicating the short vowel sound. Therefore, the spelling and pronunciation of "Bathbun" are closely related.