Definition of long grass in US English:

long grass

noun

  • 1Used generally: tall grass or grass-like growth, which is tall enough, for example, to conceal animals.

  • 2British (originally and chiefly Politics). "to kick (a person or thing) into the long grass" and variants: to put aside, defer; to sideline.

Origin

Late 17th century; earliest use found in William Dampier (1651–1715), buccaneer and explorer. From long + grass.