Tarmac

Tarmac was a tar-based construction material that was pliable and gooey when hot, but extremely hard when cooled. It was often used in the construction of roads.

The Tenth Doctor and Martha Jones once used a spot of freshly-laid tarmac to capture a sabre-toothed tiger that had escaped from the Museum of the Last Ones. After luring it into the hot tarmac, the Doctor used his sonic screwdriver to rapidly cool the tarmac and freeze the tiger's paws. (PROSE: The Last Dodo ^[+]Loading...["The Last Dodo (novel)"])

While at a ball in 1813, the Fifteenth Doctor advised Ruby Sunday not to "accidentally invent tarmac", adding that 1902 had "got away from [him]". (TV: Rogue ^[+]Loading...["Rogue (TV story)"])