herd grass meaning

or herd's grass /hûrd(z) gräs/ (US)
  noun
1. Timothy
2. Redtop
  ORIGIN: From John Herd, who observed timothy in New Hampshire, 1700

• herd's grass:    Noun: herd's grass ...
• herd:    Noun: herd &n ...
• herd immunity:    [Medicine]The non- ...

Examples

1. The station is mentioned in the Annual Report of the American Institute, on the Subject of Agriculture, Volume 6, and in the Annual Report of the American Institute of the City of New York also in 1848, which describes a growth of herd grass by the train.