A Church

1. (countable) A Christian house of worship; a building where Christian religious services take place. [from 9th c.]
2. Christians collectively seen as a single spiritual community; Christianity. [from 9th c.]
3. (countable) A local group of people who follow the same Christian religious beliefs, local or general. [from 9th c.]
4. (countable) A particular denomination of Christianity. [from 9th c.]
5. (uncountable, countable, as bare noun) Christian worship held at a church; service. [from 10th c.]
6. (uncountable) Organized religion in general or a specific religion considered as a political institution.
7. (informal) Any religious group. [from 16th c.]
8. (obsolete) Assembly.

Usage notes

• Several senses of church are routinely used in prepositional phrases as a bare noun, without a determiner or article. This is like home and unlike house.
• (organized religion): Often capitalized as "(the) Church" without referring to a specific formal institution with that title.

Synonyms

• autem (obsolete, Britain, thieves’ cant)
• (building): chapel (small church), kirk (Scotland)
• (group of worshipers): congregation