WordWeb Online

1. Bristling with perplexities
   "the thorny question of states' rights"
    
2. 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

Derived forms: thornier, thorniest

See also: armed, difficult, hard, thorn, thorniness