The Japanese word "origami" itself is a compound of two smaller Japanese words: "ori" (root verb "oru"), meaning to fold, and "kami", meaning paper. Until recently, not all forms of paper folding were grouped under the word origami. Before that, paper folding for play was known by a variety of names, including "orikata", "orisue", "orimono", "tatamigami" and others. Exactly why "origami" became the common name is not known; it has been suggested that the word was adopted in kindergartens because the written characters were easier for young children to write. Another theory is that the word "origami" was a direct translation of the German word "Papierfalten", brought into Japan with the Kindergarten Movement around 1880.