Dictionary.net

• ubiquitous European annual weed with white flowers and finely divided leaves naturalized and sometimes cultivated in eastern North America; sometimes included in genus Matricaria

2006 - WordNet 3.0
By Princeton University

• ubiquitous European annual weed with white flowers and finely divided leaves naturalized and sometimes cultivated in eastern North America; sometimes included in genus Matricaria

2011 - English Dictionary Database
By DataStellar Co., Ltd