The phrase "haddest aversion to" is an archaic form of the sentence "you had a strong dislike for." The spelling of "haddest" is pronounced as /ˈhædɪst/ in IPA phonetic transcription, and its modern-day counterpart is "had." "Aversion" is pronounced as /əˈvɜːʃən/ and means a strong dislike or opposition towards something. This phrase is commonly found in older literature and shows the evolution and changes in the English language over time.