What does "drab" mean?

Additional senses

1. 2.A wooden box, used in salt works for holding the salt when taken out of the boiling pans.
2. 3.To associate with strumpets; to wench. Beau. & Fl.
3. 4.A kind of thick woolen cloth of a dun, or dull brownish yellow, or dull gray, color; -- called also drabcloth.
4. 5.A dull brownish yellow or dull gray color.
5. 6.Of a color between gray and brown. -- n. A drab color.