Answer:

woads

Answer	Crossword Clue
WOADS	Blue dyes
WOADS	Blue-dye plants
WOADS	Blue dyes from a plant.

WOADS	Blue dye plants.
WOADS	Blue dyes.
WOADS	Blue dyestuffs.
WOADS	Dye herbs
WOADS	Certain dyes
WOADS	Dye-yielding mustard plants

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.