pep (one) up
To increase or enhance one's excitement, interest, energy, or alertness. The show was going really poorly until the host came out and pepped the audience up. I think I need some coffee to pep me up.
pep (something) up
To make something more interesting, engaging, or exciting. I always use some red chilies to pep up my soups and stews. Have you considered using electric guitars to pep the song up a bit?
pepped (up)and peppy
mod. alcohol intoxicated. (see also perked (up).) That guy looks a little pepped up. Don’t give him any more booze.