- crabgrass, crab grass, finger grass - grasses with creeping stems that root freely; a pest in lawns
--1 is a kind of grass
--1 is a member of Digitaria, genus Digitaria
--1 has particulars:Egyptian grass, crowfoot grass, Dactyloctenium aegypticum; smooth crabgrass, Digitaria ischaemum; large crabgrass, hairy finger grass, Digitaria sanguinalis