A verb from an old language that nobody can completely decipher, but mimics English. Scholars predict that it spoke to the lifespan of a leaf. Leaves
change colors and then fall, so it must mean
something along the lines of growing up or changing. Although, there has been at least one crackpot theory undoubtedly made by a stressed college student at 3 AM, that stated that the verb meant
literally turning into a leaf.