Similar words
rapidez
rapidez is more about quickness or swiftness in general; velocidad is more technical or measurable, like speed in km/h, physics — both mean "speed."
Similar in other languages
Portuguese
velocidade
velocidade is the Portuguese word for the same thing — both mean "speed."
Practice
1 What does velocidad mean?
speed
2 Fill the gap: Respeta el límite de ___.
Full sentence: Respeta el límite de velocidad. (Respect the speed limit.)
3 Which fingerprint chart matches velocidad?
velocidad: neutral register, core frequency, general domain, neutral connotation.