knotgrass

• POS: Noun
• HYPHEN: knot=grass

CIDE DICTIONARY

knotgrass, n. 

 a common weed with jointed stems (Polygonum aviculare); knotweed.  [1913 Webster]
" An infusion of Polygonum aviculare was once supposed to have the effect of stopping the growth of an animal, and hence it was called, as by Shakespeare, “hindering knotgrass.”"  [1913 Webster]
"We want a boy extremely for this function,
Kept under for a year with milk and knotgrass."  [1913 Webster]

OXFORD DICTIONARY

knotgrass, n.
1 a common weed, Polygonum aviculare, with creeping stems and small pink flowers.
2 = POLYGONUM. Also called KNOTWEED.