Petrichor

Petrichor  was, as defined by the TARDIS Matrix when inhabiting the body of Idris, the smell of dust after rain. The word was used by the TARDIS as part of the passkey to open a back-up TARDIS control room, which she gave to Rory through a telepathic link. (TV: The Doctor's Wife) Petrichor was also the name of a fragrance for which Amy Pond posed as a model for in an advertisement. Its slogan was "For the girl who's tired of waiting." This modelling job with Petrichor apparently made her famous. (TV: Closing Time)