The spelling of the phrase "wast on guard" can be confusing due to the silent letters used in this phrase. The word "wast" is pronounced /wɑːst/ and is an archaic form of the verb "was". The second part, "on guard", is pronounced /ɒn ɡɑːd/ and means to be alert and watchful. Together, the phrase means to be alert or vigilant. While the spelling can be tricky, understanding the IPA phonetic transcription can help in correctly pronouncing and using this phrase.