Crab grass Meaning, Definition & Usage

  1. noun grasses with creeping stems that root freely; a pest in lawns
    finger grass; crabgrass.

WordNet

Definitions
  1. . (Bot.) (a) A grass (Digitaria, ∨ Panicum, sanguinalis); called also finger grass. (b) A grass of the genus Eleusine (E. Indica); called also dog's-tail grass, wire grass, etc.

Webster 1913