text: The modern definition is the occurrence of two full moons in a month  is termed as Blue moon.The earliest known recorded usage was in 1528, in a pamphlet entitled Rede Me and Be Not Wrothe: "Yf they say the mone is belewe, we must believe that it is true". This implies the expression had a meaning of something that was absurd, and bears close resemblance to another moon-related adage first recorded in the following year "They woulde make men beleue ... that ye Moone is made of grene chese".