Pronunciation: [hˈadst ˈʌp] (IPA) 
The spelling of the word "hadst up" is unique and can be confusing for many people. This archaic term is a combination of two words: "hadst" and "up," which are both pronounced separately. "Hadst" comes from the Old English word "hæfde" which means "had" and is pronounced as "hædst." On the other hand, "up" is a common English word pronounced as "ʌp." When combined, the phonetic transcription of "hadst up" would be /ˈhædst ˈʌp/.
"Hadst up" is a phrase in Early Modern English and specifically refers to the second person singular form of the verb "to have" in the past tense.
The word "hadst" is a combination of "had" and the second person singular ending "-st". "Had" originally comes from the Old English word "habban", which means "to have, to hold". In Middle English, the past tense form of "habban" was "hadde". Over time, the "-de" ending was dropped, and "had" remained as the past tense form.
The second person singular ending "-st" was often added to verbs in Early Modern English to indicate that the subject of the sentence was "thou" (you, in the modern sense). It denoted singular informal usage.
