Generally, the word, skeptic, means one who doubts or disagrees. This can apply to doubts about anything. For example, a person might be skeptically about insignificant things, such as the train arriving at the station on time. Specifically, the word, agnostic, refers to one who rejects the ideas of faith, the church or religion because he thinks it is impossible to know the truth. A person who calls himself an agnostic would be skeptical about his belief in God. The word, macabre, means something that is gruesome, frightful or repugnant. I certainly wouldn't use this word as a synonym for either skeptical or agnostic. In some cases, I would use the word, SUSPICIOUS as a synonym for SKEPTICAL. In some cases, I would use the word, IRREVERENT or COMTEMPTOUS for SKEPTICAL. It would depend on the type of situation. Hope this helps