The English language is made up of thousands of words that can be traced back to many root languages — we can find evidence of Latin, Greek, and Germanic roots, as well as Sanskrit, Hebrew, and lesser-known dialects. But sometimes words make their way into the English lexicon purely by mistake. “Rumbustious” is one such neologism (new word). At some point in the late 18th century, the archaic word “robustious,” meaning “boisterous and robust,” was mistakenly used as “rumbustious.” The error stuck, and now the unruly word is recorded in the dictionary.