Synonyms of the word 
THORNLESS → SPINELESS - UNARMED
thornless
- adj. Without thorns.
spineless
- adj. Having no spine.
- adj. Cowardly; uncourageous.
unarmed
- adj. Defenceless and lacking weapons or armour.
- adj. Not carrying arms.
- adj. (biology) Not having thorns or claws etc.
If you are interested in words, visit the following sites :
- wiktionary.org/thornless For complete definition of a word
- 1word.ws/thornless to play with words, suffixs, prefixs, etc.