Definition of "chapstick"

I kissed a girl and I liked it / The taste of her cherry chapstick / I kissed a girl just to try it / I hope my boyfriend don't mind it

2008 April 28, Katy Perry, Dr. Luke, Max Martin, Cathy Dennis, “I Kissed a Girl”, in One of the Boys, performed by Katy Perry

After the kiss, she pulled out her chapstick and put it on.

2009, Laura Francois, Reckless Perfection, page 74