A word a day
I had the impression that 'pep' was a slang word since the only usage I had encountered previously was in the phrase 'pep talk'. At least that was until I looked it up in the dictionary:
Pep (noun): brisk energy or initiative and high spirits
pep. (2009). In Merriam-Webster Online Dictionary. Retrieved February 21, 2009, from http://www.merriam-webster.com/dictionary/pep