The word 'hiking' is understood in all English-speaking countries, but there are differences in usage. In some places, off-trail hiking is called 'cross-country hiking', 'bushwhacking', or 'bush-bashing'. In the United Kingdom, hiking is a slightly old-fashioned word, with a flavor more of heartiness and exercise than of enjoying the outdoors; the activity described here would be called 'hillwalking' or simply 'walking'. Australians use the term 'bushwalking' for both on- and off-trail hiking. Hiking in the mountainous regions of India and Nepal is sometimes called 'trekking'. Overnight hiking is called 'backpacking' in some parts of the world (Wikipedia).