petrichor

noun

1. (uncountable)The distinctive scent, caused by geosmin, which accompanies the first rain after a long, warm, dry spell.

   “Though it had yet to begin raining, the familiar smell of petrichor appeared to be already present and Neelam suddenly wished she was sitting at home with a nice cup of tea and a good book.”

   “The sources of the heavenly scent during and immediately after it rains are petrichor and geosmin. Petricor is an oil produced by plants then absorbed by rocks and soil and released into the air during rainfall.”

2. (uncountable)The yellow organic oil that yields this scent.

   “He hypothesizes that this factor may be petrichor, an oil which has been isolated from silicate minerals and rocks[…].”