Cleave, dust, and screen are all words that can mean the opposite of themselves. You can cleave to a belief, meaning to “adhere closely,” but you can also separate things by cleaving them. Words that mean the opposite of themselves go by many different names, including contranyms, contronyms, auto-antonyms, and Janus words. Lists from an MIT teacher, Polysemania Blog, and this website on English Word Information. Martha talks about enantiodromia, which is “the process by which something becomes its opposite,” particularly when an individual or community adopts beliefs antithetical to beliefs they held earlier. This is part of a complete episode.