have i ever posted about The Dundancy of Erous on here?

The existence of the prefix "re-" on "redundant" implies an opposite state of "dundant." Whereas "redundant" means "able to be omitted without loss of meaning," "dundant" would be the state of being unable to omit any information.

This brings us to the word "preposterous." Since it has both pre- and post- prefixes, its dundant form would just be "erous." We can make language more succinct by applying this logic to other words. And now you understand how erous is dundant.