Skepticism, in Bertrand Russell's words, means "it is undesirable to believe a proposition when there is no ground whatever for supposing it true. " I.e. don't believe until there is enough evidence.
For example, Newton's laws are supported by experiments, therefore there is sufficient evidence. On the other hand, Marxism was made up by Karl Marx, and before the Soviet Union, there were no systematic experiments, therefore we should be skeptical about Marxism.
When skepticism is translated into Chinese, it becomes 怀疑态度，怀疑论； 多疑癖, which means the practice of suspicion, a tenancy to believe even though the evidence is unclear.