The phrase "most exceeding" typically means something that is surpassingly great or exceptional. The antonyms for this phrase would be words that express the opposite sentiment, such as ordinary, mediocre, substandard or average. For instance, instead of using "most exceeding," you could use words like unspectacular, commonplace, insufficient, or trivial to convey an opposite meaning. It is essential to use the right antonyms according to the context in which the phrase is used. For example, in a positive sense, you could use antonyms like unremarkable or ordinary, while in a negative context, antonyms like decent or good may be more appropriate.