Petrichor

Petrichor, as defined by the TARDIS Matrix when inhabiting the body of Idris, was the smell of dust after rain. It was used by the TARDIS as part of the password to open a back-up TARDIS control room, which she gave to Rory through a telepathic link. (TV: The Doctor's Wife) Sarah Jane Smith loved "that fresh smell just after a rain shower". (TV: The Android Invasion)

Petrichor was also the name of a fragrance for which Amy Pond posed as a model in an advertisement. Its slogan was, "For the girl who's tired of waiting." (TV: Closing Time) The alien Krampus once showed Veronica Stackmore an image of Amelia Pond's future Petrichor advertisement and in an attempt for Veronica to wish Amy, Rory, and Mels out of existence he stated, "Amelia's beauty eclipses you! She will be loved and applauded while you are forgotten!" (COMIC: Imaginary Enemies)