1.
a. : a weedy lettuce that is an escape from a cultivated strain
b. : any of several native wild plants of the genus Lactuca: as
(1) : prickly lettuce
(2) : a blue lettuce (L. pulchella)
(3) : a tall No. American herb (L. canadensis) that resembles prickly lettuce but lacks spines
2. : false wintergreen
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any of various uncultivated species of lettuce, growing as weeds in fields and waste places, esp. a North American species, Lactuca canadensis.
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wild lettuce,
any uncultivated species of lettuce growing as a weed, especially a prickly-stemmed European species with yellow flower heads.
Useful english dictionary. 2012.