Nop,"condemn" is the antonym of appreciate and "regard" is the antonym of disregard.to regard someone is a different thing,disregard means,do not respect someone.suppose somebody has done a favour...
The opposite (antonym) of antonym is synonym. An antonym is a word that means the opposite. A synonym is a word that means the same thing, or nearly the same thing, for a given context.
Some words do not have direct opposites [antonyms]. Antonyms do not usually substitute for phrases. The phrase "you are" has no antonym. A contrasting version of "you are" is "you are not".