The term "most neverfailing" implies that something or someone is extremely reliable or consistent. To find antonyms for this phrase, we need to look for words that mean the opposite of these qualities. Some antonyms might include "unreliable," "inconsistent," "erratic," or "unpredictable." These words describe things or people that cannot be counted on to consistently perform or behave in a certain way. Using antonyms like these can help add contrast to a piece of writing or conversation, highlighting the stark difference between two opposing ideas or concepts.