Definition of "holt"

As over Holt and Heath, as thorough Frith and Fell;

1612, Michael Drayton, Poly-Olbion, song 11 p. 174

[the gale] 'Twould blow like this through holt and hanger.

1896, A. E. Housman, A Shropshire Lad, XXXI, line 5

Once, at our cottage at Dodford, a tiny thatched village under a steep holt full of foxgloves...

1977, Patrick Leigh Fermor, A Time of Gifts