"vigor, energy," 1912, shortened form of pepper (n.), which was used in the figurative sense of "spirit, energy" from at least 1847. Pep rally is attested from 1945; pep talk from 1926. To pep (something) up is from 1925.
实用例句
1. Powell spent the day giving pep talks to the troops.
鲍威尔花了1天时间为部队作动员讲话。
来自柯林斯例句
2. The Democrats held a pep rally on Capitol Hill yesterday.
民主党昨天在国会山召开了竞选誓师大会。
来自《权威词典》
3. I gave him an extra dose of glucose to pep him up.