skeptical

Etymology

skeptic + -al

adj

1. Having, or expressing doubt; questioning.
   Numerous experimental tests and other observations have been offered in favor of animal mind reading, and although many scientists are skeptical, others assert that humans are not the only species capable of representing what others do and don’t perceive and know. 2012 March-April, Colin Allen, “Do I See What You See?”, in American Scientist, volume 100, number 2, archived from the original on 2012-04-26, page 168
   My teacher was skeptical when I told her my dog ate my homework.
   I can see why people are so skeptical [sic] about him, but I think he's on to something here. (regarded by organizations such as the BBC as an error)
   Tom was skeptical when Paul told him that he saw Bigfoot.
2. Of or relating to philosophical skepticism or the skeptics.