Real Dictionary

woodruff in American English
any of a genus (Asperula) of plants of the madder family, with small, white, pink, or blue, lily-shaped flowers; esp., a European species (A. odorata) used to flavor wine and in perfumery
noun: any of several plants belonging to the genus Asperula or Galium, of the madder family, as G. odoratum (sweet woodruff), a fragrant plant with small white flowers

woodruff in British English
noun: any of several rubiaceous plants of the genus Galium, esp G. odoratum ( sweet woodruff), of Eurasia, which has small sweet-scented white flowers and whorls of narrow fragrant leaves used to flavour wine and liqueurs and in perfumery