Going to sleep now, but still thinking about the reformation and its
effects on folk/culture/language. There are 3 Icelandic words that are
typically used about the reformation, all meaning the 'reformation'.
The correct one depends on the personal views of the person you are
talking to (all w/ the article here, as there was 'one' reformation):
siðbótin
siðbreytingin
siðaskiptin
The last is the most neutral-sounding/least offensive, and the most
commonly used, but there are folk who use the others as well. Siður
(ON siðr) in this context means 'religion/custom'. skipti, breyting
and bót are all in Zoega and Cleasby/Vigfússon (and modern orðabækur).
The compounds are all Modern Icelandic. No comments on the 'correct'
one ;)