dry shampoo       
noun [ C or U ] uk/ˌdraɪ ʃæmˈpuː/ us/ˌdraɪ ʃæmˈpuː/
 (头发)干洗香波
a substance that you can put on your hair to make it look and feel cleaner, without needing to use water
  If your hair feels a little greasy, spray on some dry shampoo. 如果你的头发感觉有点油腻,就喷上些干洗香波吧。 
 I use a spray-in dry shampoo. 我用的是喷雾式干洗发水。 
 - More examples
 - Dry shampoo is my secret style tip - it's great on tour when I'm living on a bus and can't wash my hair for a week.
 - In her room she had a bottle of dry shampoo that she used between washes.
 - On holiday I can't live without this dry shampoo, which revives, refreshes, and adds body to my locks.
 - To get this look, don't wash your hair every day and use a dry shampoo in between.