From the ArcaMax Publishing, Vocabulary Newsletter:
http://www.arcamax.com/news/vocabulary/s-340071-413308
Zeitgeist \TSYT-guyst; ZYT-guyst\ (noun) - [Often capitalized] The
spirit of the time; the general intellectual and moral state or temper
characteristic of any period of time.
"Yet being a man, as I say, with his hair a little stirred by a
Zeitgeist that made for change, Gates did at times display a
disposition towards developments." -- Herbert George Wells, 'The New
Machiavelli'
Zeitgeist is from the German: Zeit, "time" + Geist, "spirit."