Question

difference between excellent and outstanding ...

Answer 1

As adjectives the difference between outstanding and excellent

is that outstanding is prominent or noticeable; standing out from others while excellent is of the highest quality; splendid. 

As an adverb excellent is

 (obsolete) excellently.

Answer 2

outstanding is prominent or noticeable; standing out from others while excellent is of the highest quality; splendid. And excellent used for the noble. But both have the same meaning we can say so.
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