The word is — cough — in the air. But where does it come from? The Oxford English Dictionary has it:
ˈTarmac, n .Proprietary, capitalized: huh. The Dictionary’s earliest citation is from 1903.
A kind of tar macadam consisting of iron slag impregnated with tar and creosote; also designating a surface made of tar macadam. Now freq. with lower-case initial. the tarmac (colloq.), the airfield or runway.
A proprietary name in the United Kingdom.
[Context: Bill Clinton’s confab with Loretta Lynch as their planes were parked on the you-know-what. I’m surprised to see that tarmac is missing from the list of trending words at Merriam-Webster.]