dūmus (old form dusmus, v. dumosus), i, m. [dusmus for densimus, from densus],
a thorn-bush , bramble , Cic. Tusc. 5, 23, 65; Verg. G. 3, 315; 338; 4, 130; id. A. 4, 526 et saep.
(dūmus ī), m a thorn-bush, bramble. — Only plur, a thicket: e dumis eminens: silvestres, V. ...
An Elementary Latin Dictionary