Mac Dictionary’s definition:
1 a person inclined to question or doubt all accepted opinions.
• a person who doubts the truth of Christianity and other religions; an atheist or agnostic.
2 Philosophy an ancient or modern philosopher who denies the possibility of knowledge, or even rational belief, in some sphere.
The leading ancient skeptic was Pyrrho, whose followers at the Academy vigorously opposed Stoicism. Modern skeptics have held diverse views: the most extreme have doubted whether any knowledge at all of the external world is possible (see solipsism ), while others have questioned the existence of objects beyond our experience of them.
another term for skeptical .
skepticism |ˈskeptəˌsizəm| ( Brit. scepticism) noun
ORIGIN late 16th cent. (sense 2) : from French sceptique, or via Latin from Greek skeptikos, from skepsis ‘inquiry, doubt.’
I’m skeptical of York University’s security policies.