Mystifying
Part of speech: adjective
Definition: unusual
Part of speech: verb
Definition: To thoroughly confuse, befuddle, or bewilder.
Incomprehensible
Part of speech: adjective
Definition: impossible or very difficult to understand
Example sentence: To say that a work of art is good, but incomprehensible to the majority of men, is the same as saying of some kind of food that it is very good but that most people can't eat it.