Antonyms for the word modernities are mainly related to traditional or ancient practices, beliefs, and customs. Some potential antonyms include outdated, obsolete, archaic, primitive, antiquated, old-fashioned, and traditional. These words imply that modernities are contrary to the practices that have been followed for centuries. However, it is important to note that the application of antonyms depends on the context in which the word is used. For instance, in a technological context, antonyms for modernities could be backward, behind the curve or outmoded. Ultimately, the use of antonyms for modernities can vary greatly based on the perspective of the speaker or writer.