Pronunciation: [wɒst kˈʌmɪŋ] (IPA) 
The proper spelling of the phrase "wast coming" is actually "wasn't coming". The word "wasn't" is a contraction of "was not". The apostrophe takes the place of the "o" in "not". The phonetic transcription of "wasn't" is /ˈwʌznt/, where the /z/ sound represents the contraction of "not". So, if you come across the spelling "wast coming", know that it is incorrect and the correct spelling is "wasn't coming".
The phrase "wast coming" does not have a specific etymology as it is a combination of two words: "wast" and "coming".
The word "wast" is the second person singular past tense of the verb "be" in Early Modern English (16th and 17th centuries), often used in question form. Nowadays, we use "were" instead of "wast". For example, "Thou wast coming" can be translated to "You were coming".
The word "coming" is the present participle form of the verb "come", meaning to move towards or approach a certain place. It is derived from the Old English word "cuman" or "cyme" which had a similar meaning.
Therefore, in the context of "wast coming", the phrase would mean "you were coming" in modern English.
