The phrase "doeth vanishing act" could be defined as disappearing suddenly without any explanation or warning. When we think of antonyms for this phrase, words such as appearing, revealing, and appearing suddenly come to mind. Antonyms for "doeth vanishing act" could include words like "appear," "show," "emerge," "present," and "manifest." These words convey the opposite meaning of "doeth vanishing act" and suggest something that is visible, present, and in plain sight. Therefore, if you want to talk about something that is visible and apparent, you might use these antonyms to convey your message effectively.