Minced Oath

No, it is not a spicy oath. 'Bye George, by George we’ll miss ya!'  The minced oath, “by George” where one letter - ‘g’ word is substituted for another ‘g’ word. In this case, the second George is substituted for God, because some people did not believe in God. The use of George came into use around the turn of the 20th century and usually meant great or OK, as in ‘everything is George’.