Being tantamount to is a phrase that usually indicates equality or likeness in meaning or value. Its antonyms, therefore, could be any word or phrase that denotes the opposite; dissimilarity or inequality. Some antonyms of being tantamount to include incongruent, discrepant, dissimilar, unequal, and opposite, among others. Being incongruent signifies a complete lack of harmony or similarity, whereas discrepant means being inconsistent or contradictory in nature. Dissimilar suggests having no commonality or likeness, while unequal denotes a lack of balance or similarity in value. Opposite means being diametrically opposed in meaning, nature or character. Understanding the antonyms of being tantamount to can help you better express the intended meaning of a statement.