no-poo; washing hair with water only
A method of washing hair using only hot water, without shampoo or other products. Often associated with natural hair care routines.
Since I started washing my hair with just hot water, my hair has been in better condition.
No-poo is said to be environmentally friendly because it doesn't use shampoo.
Abbreviation of お湯 (hot water) + シャンプー (shampoo), literally 'hot-water shampoo'. The term likely originated in Japanese natural hair care communities.