big-bang theory: (cosmology) the theory that the universe originated sometime between 10 billion and 20 billion years ago from the cataclysmic explosion of a small volume of matter at extremely high density and temperature
boletus pallidus: a fungus that has an off-white cap when it is young but later becomes dingy brown and a stalk of the same color; the under surface of the cap (the tubes) a pale greenish yellow