The word "jointliest" is spelled with a unique combination of letters that can be challenging to phonetically decipher. The IPA phonetic transcription for "jointliest" is /dʒɔɪntlɪst/, which consists of the consonants "j", "t", "l", and the vowels "o", "i", and "e". This word is the superlative form of "jointly", meaning most jointly or having the most joint effort. While the spelling may be difficult to understand, using proper phonetic transcription can help to clarify the pronunciation of the word.