The word "scadsest" is not found in any English language dictionaries and seems to be a made-up term. However, if we try to find synonyms for it based on the sound of the word, we can suggest several alternatives such as miscreant, mischievous, scallywag, rascal, and ne'er-do-well. These words are often used to describe a person who is up to no good or behaves in a way that is considered dishonest or immoral. They can also indicate a sense of playfulness or naughtiness, which is often associated with children or pranksters. It's important to note that while these words may share some similarities with "scadsest" in terms of connotation, they are not true synonyms of the non-existent term.