1. the process of making something white or whiter
2. a substance used to make something white or whiter

1. present participle of whiten; making or becoming white or whiter

Examples

• The whitening of her hair happened gradually over several years.
• She used a tooth whitening treatment to brighten her smile.
• The whitening agent in the detergent removed the stains effectively.
• The snow was whitening the landscape as it continued to fall.
• Professional teeth whitening can be expensive but effective.
• The whitening cream promised to lighten dark spots on the skin.
• His beard was whitening at the temples as he aged.