http://oakden.co.uk/kendal-mint-cake-recipe/
It's a slab of peppermint-flavoured sugar, doused in glucose syrup, covered in chocolate.
It's one of those things that you cannot possibly imagine yourself eating, until you're actually out on the hills after a long day (or several days) and you're cold and you're tired and then you've never eaten anything quite so delicious.
Yes we do.
I would just call it walking, or tabbing if it's at an aggressive pace. Old people seem to call it rambling, but that makes it sound a bit lazy I think.
OED, which I'd trust more than Wiktionary, says 'colloq. orig. dial. and U.S.' and gives US examples prior to the 20s.
Almost all American English words are originally of English origin, of course ;)
However, Google Ngrams shows that the term "hiking" was very rare prior to about 1920, and the large majority of 1920s sources are American. https://books.google.com/ngrams/graph?content=hiking&year_st...
Compare hiking, hill walking, tramping, and rambling: https://books.google.com/ngrams/graph?content=hiking%2Chill+...
Tabbing tends to be a military term as far as I'm aware. I don't remember using the term hiking until recently.
The MilFit community have brought it into mainstream usage. I don't remember not using/hearing the term hiking.