Complex sentence: It is not known as to when the term "Green Boots" came into Everest parlance, but it became lexicon down the years as all the expeditions from the north side encountered the body of the Indian Climber curled up in the limestone alcove cave.
Split into simpler sentences: It is not known as to when the term "Green Boots" came into Everest parlance. Over the years it became a common term as all the expeditions from the north side encountered the body of the Indian Climber curled up in the limestone alcove cave.