greenweed n small Eurasian shrub having clusters of yellow flowers that yield a dye; common as a weed in Britain and the United States; sometimes grown as an ornamental Usage(s) Rather than sacrifice himself at the command of a Congo witch-doctor he will shoot his sixth, silver bullet at a squirming, greenweed crocodile. Synonym(s) woodwaxen dyer's greenweed dyer's-broom dyeweed whin woadwaxen Genista tinctoria