This phrase can refer to:
- Old Nassau, Princeton's alma mater since 1859, with words by then-freshman
Harlan Page Peck and music
by Karl A. Langlotz. The
words of the first verse are:
- By metonymy, Princeton University itself.
- Nassau Hall, to which the song refers, built in 1756 and named after William III, King
of England, Prince of Orange and Nassau. When built, it was the largest college building in North America. It served briefly as
the capitol of the United States when the Continental Congress convened there in the summer of 1783.
- A chemical reaction, an example of a "clock reaction," dubbed "Old Nassau" because the solution turns first orange and then
black, the Princeton colors. It is also known as the "Hallowe'en reaction."