changing to a lighter color
"After years of living at high altitude, his skin has gradually taken on a pale whitening hue from the intense sun exposure."
A substance, such as a bleach, used to make something white or whiter.
"She added a few drops of whitening agent to her laundry water to get those stained socks back to their original brightness."
present participle of whiten
"The old woman spent her mornings scrubbing the kitchen floor, slowly turning the grime-stained tiles into a bright expanse through relentless whitening."