This is a newer word, another of my very favourites, and one that would really benefit from a scratch and sniff app.
Pronunciation: Pe- tri-kor
noun 1. A pleasant smell that frequently accompanies the first rain after a long period of warm, dry weather
Etymology: coined in 1964 by two Australian researchers, Bear and Thomas, for an article in the journal Nature. In the
article, the authors describe how the smell derives from an oil exuded by certain plants during dry periods, whereupon
it is absorbed by clay-based soils and rocks. The word is a blend of the Greek petro 'relating to rocks' and ichor, the
fluid that flows in the veins of the gods in Greek mythology.
Sources: Oxford English Dictionary and Wikipedia
Erin Bedford, writer.