The Swedes also have Frokost at breakfast. The word, via germanic roots, means "early food" (present day German früh = early) and used to denote a meal taken before noon (as made sense when farm workers rose with the sun), but not necessarily the first meal, which would be "morgenmad", or "morning food" in all three languages (and a much simpler meal, as nobody was up to prepare it, as opposed to the later meal). From there, as this meal became more redundant, the word drifted earlier in the day in Norwegian and Swedish to become breakfast, and later in Danish to become lunch.

The large meal taken in the middle of the day was "middagsmad", or "midday food" (still is in the older generations, especially rurally, in Denmark), while "middag" is generally the larger, evening meal today (so, same deal as "dinner" in English).

Interesting. Fenno-Swedish did away with "frukost", and the only morning meal is "morgonmål". Though I remember reading about someone having separate "morgonkaffe" and "frukost" as a child, and thinking it very strange...