The description of the word you requested from the astronomical dictionary is given below.
albedo = [Latin] white paint or color
The albedo of an object is a number between 0 and 1 that indicates which fraction of incoming light is immediately reflected by the object. The albedo of the Earth is about 0.3: the Earth and its atmosphere reflect about 30 percent of the sunlight that hits them. All other things being equal, a planet looks brighter and has a lower temperature when its albedo is greater.