If you are sceptical about something, you have doubts about it.
例句
Other archaeologists are sceptical about his findings.其他考古学家对他的发现表示怀疑。...scientists who are sceptical of global warming and its alleged consequences...对全球变暖和各种断言的后果持怀疑态度的科学家
英汉词典释义
adj.
不肯相信的; 常怀疑的
I am rather sceptical about their professed sympathy for the poor.他们声称同情穷人, 我对此相当怀疑。
英英词典释义
Adjective
1. marked by or given to doubt;
"a skeptical attitude""a skeptical listener"
2. denying or questioning the tenets of especially a religion;