What is the definition of visible white light wave (roygbive)

There's no such thing as a wave of white light.  Every light wave with
a certain wavelength has some color.  White light is a mixture of all
the different wavelengths with all of the different visible colors. 
They're ALL there in white light.  When they all enter your eye at
the same time, your brain gets the message of brightness with
no particular color, which we call "white light".