1. Having or covered with protective barbs or quills or spines or thorns or setae etc.
   "a horse with a short thorny mane";
   - barbed, barbellate, briary, briery, bristled, bristly, burred, burry, prickly, setose, setaceous, spiny
    
2. Bristling with perplexities
   "the thorny question of states' rights"

Derived forms: thornier, thorniest

See also: armed, difficult, hard