The Word of the Day

epoch \EP-uhk\, noun:

1. The beginning of a distinctive period in the history of anything.
2. A particular period of time marked by distinctive features or events.
3. A memorable date.
4. Geology. Any of several divisions of a geologic period during which a geologic series is formed. Compare age.
5. Astronomy. An arbitrarily fixed instant of time or date, usually the beginning of a century or half century, used as a reference in giving the elements of a planetary orbit or the like. b.The mean longitude of a planet as seen from the sun at such an instant or date.
6. Physics. The displacement from zero at zero time of a body undergoing simple harmonic motion.