What does skeptical mean?

Answer 1

Skeptical means to be open minded and consider all the facts before making a conclusion.

Answer 2

The adverb skeptically pertains to something done with some doubt or uncertainty as to its truth or validity. Someone may skeptically accept (have misgivings) or skeptically observe (with a doubting eye, or out to disprove a concept).

Answer 3

Skepticism means doubt or misgivings. A skeptic is one who questions a doctrine or fact.

Philosophy

Skepticism refers to the comprehensive doctrine which describes absolute knowledge as impossible to acquire and the closest we can come to absolute knowledge is to believe it to be true. Philosophical skeptics are people who question the truth of everything and have not accepted any legitimate source of knowledge.
Originally a philosophical system involving the systematic doubt of accepted propositions, colloquially it means doubt about the truth of a particular statement.
Being a skeptic is an art in itself. It doesn't mean blindly doubting everything that is asserted.