Definition:

the spirit of the time; the general moral, intellectual, and cultural climate of an era

Example:

"Twitter provides an insight into the minute-by-minute zeitgeist of the internet." – Nicholas Pell, GoBankingrates.com, September 29, 2011

About the Word:

This German word (Zeit means "time"; Geist means "spirit") is usually associated with the philosopher who popularized it, Georg Wilhelm Friedrich Hegel.