the GNU version of the Collaborative International Dictionary of English
adj. Destitute of, or free from, thorns.
The Century Dictionary and Cyclopedia
Free from thorns.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. lacking thorns
Word Usage
"Prickly wild brambles can be tamed by whacking back the edges of the thicket twice a year, and modern cultivated varieties such as thornless 'Triple Crown' blackberry make great thickets, too."