Jaap \jaap\ as a boy's name is a variant of Jacob (Hebrew), and the meaning of Jaap is "he who supplants".

The baby name Jaap sounds like Joab and Joop. Other similar baby names are Capp, Cap, Chap, Jago, Ja-, Jaray, Jace, Jacy, Jack, Jaq, Jak, Jay, Jake, Jaco, Jade, Jael, Jair, Jan, Jano, Jarah, Jary, Jase, Javi, Jaye, Jai, Jae, Jazz, Jean, Jada, Juan, Joao, Jian and Nap.