any of various grasses having slender stems and leaves, especially one of the genus Deschampsia, as D. flexuosa or D. caespitosa.
Origin of hair grass
First recorded in 1750–60
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for hair grass
any grass of the genera Aira, Deschampsia, etc, having very narrow stems and leaves
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012