1. cat- "according to, relating to, about" + hol- + -ic + -ism.
2. => "on the whole, in general, relating to all".
3. => universal, general.
4. => "of the doctrines of the ancient Church," literally "universally accepted".
5. Etymologically, the Catholic Church is the universal church, comprising all Christians.
6. General sense of "of interest to all, universal".

1. She, too, was a convert to Roman Catholicism.

她也皈依了天主教。

来自柯林斯例句

2. He converted to Catholicism in 1917.

他于1917年皈依天主教。

来自柯林斯例句

3. The main religions are Buddhism, Taoism, Islam, Catholicism and Protestantism.

中国宗教徒信奉的主要有佛教 、 道教 、 伊斯兰教 、 天主教和基督教.

来自汉英非文学 - 白皮书

4. His devout Catholicism appeals to ordinary people.

他对天主教的虔诚信仰感染了普通民众。

来自辞典例句

5. He is a convert to Catholicism.

他改信天主教.

来自辞典例句