Duncical is an uncommon word that is used to describe someone or something that is foolish or stupid. If you're looking for synonyms for this word, some great options include moronic, imbecilic, and asinine. Other synonyms could include idiotic, brainless, and senseless. If you're looking for words that imply a lack of intelligence or common sense, you might also consider using words like daft, slow-witted, or dim-witted. Ultimately, there are plenty of great synonyms for duncical that can help you convey a sense of stupidity or foolishness in your writing or speech.