ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ noun
Etymology: tumble (I) + weed
: any plant that habitually breaks away from its roots in the autumn and is driven by the wind as a light, rolling mass over the fields and prairies: as
a. : winged pigweed
b. : russian thistle
c. : any of several amaranths (as Amaranthus graecizans )