English

Noun

femtosecond ‎(plural femtoseconds)

1. A unit of time equal to 0.000 000 000 000 001 seconds and with symbol fs.
   • 2012, Mark Cendrowski, The Big Bang Theory, Season 5, Episode 18, "The Werewolf Transformation":

     Sheldon Cooper: My hair is growing at the rate of 4.6 yoctometers per femtosecond.