One Panel #133-134: 'Tectives

From "Batman Versus the Vampire, Part 2" by Gardner Fox, Bob Kane and Sheldon Moldoff, Detective Comics #32 (October 1939)

Very early in Batman's career, he must save his fiancée Julie Madison by killing vampires in their caskets with a gun. So all you pro-Batman with a gun people, I WILL accept Batman carrying a piece, but only if he's shooting up vampire dens.

From John Law, Scientective: "The Impossible Murder" by Harry Campbell, Smash Comics #4   (November 1939)
Combining words together (or "combwording") seems like such a 2016 thing to do, but the practice was alive and well in the Golden Age of Comics. Who knew!