Merriam-Webster Collegiate Dictionary - chamomile

 or camomile  noun  Etymology: Middle English camemille, from Medieval Latin camomilla, modification of Latin chamaemelon, from Greek chamaimelon, from chamai + melon apple  Date: 13th century  1. a perennial composite herb (Chamaemelum nobile syn. Anthemis nobilis) of Europe and North Africa with aromatic foliage and flower heads  2. any of several composite plants (genera Matricaria and Anthemis) related to ~; especially an annual Eurasian herb (M. recutita syn. M. chamomilla) naturalized in North America  3. the dried flower heads of ~ that are often used in making tea and that yield an essential oil possessing medicinal properties