The term is derived from the older noun churchman, which originally meant an ecclesiastic or clergyman but, some while before 1677, it was extended to people who were strong supporters of the Church of England and, by the nineteenth century, was used to distinguish between Anglicans and Dissenters.
"High" and "Low", the oldest labels, date from the late seventeenth century and originally described opposing political attitudes to the relation between the Church of England and the civil power.
Today, the "parties" are usually thought of as Anglo-Catholics, evangelical Anglicans, and Liberals and, with the exception of "High Church", the remaining terms are mainly used to refer to past history.
Cyril Garbett (later Archbishop of York) wrote of his coming to the Diocese of Southwark: I found the different parties strongly represented with their own organizations and federations...
Lazy refers to simpler worship, hazy to unclear tradition or beliefs, and crazy to excessive ceremonialism; but the author of the poem may have been a humorist.