Definition of "drabber"

In one-step hair coloring products such as Miss Clairol, where you can combine different shades, you can add drabbers, which are ashy substances that minimize the red hues that exist in your hair.I well know him For a most insatiate drabber . He hath given, Before he spent his own estate , which was Nothing to the huge mass he's now possess'd of, A hundred pound a leap

1990, Deborah Chase, The New Medically Based No-Nonsense Beauty Book, page 326