"Uncannier" is a word used to describe something that is strange or mysterious, often with a sense of eeriness or creepiness. It can be a difficult word to find synonyms for, but some options could include "mysterious," "unnerving," "strange," "peculiar," "weird," "spooky," or "unsettling." Other possibilities might include "unnatural," "otherworldly," "enigmatic," "haunting," or "ghostly." Depending on the context, other descriptors like "perplexing," "bizarre," "uncanny," or "disconcerting" could also be appropriate. Overall, the key is to find words that convey a sense of unease or discomfort, without being too specific or heavy-handed.