double Meaning-Background

A double meaning is defined as "(A) play on words, bringing sytactic quality of expression to the words themselves, supported ambiguously by illustration." The image of the two objects coming together resembles the "double" part in the idea of "double header". While the idea of those objects resembling head protective gear preferrably for football players is an example of the "header" part because they appear to be head-butting each other as seen in soccer which is also known as a "header". Therefore, putting these connotative meanings together equals the phrase meaning two games or sporting events shown in one night, a "double header".