thorny
     adj 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 bristly
        mane"; "bristly shrubs"; "burred fruits"; "setaceous
        whiskers" [syn: {barbed}, {barbellate}, {briary}, {briery},
         {bristled}, {bristly}, {burred}, {burry}, {prickly}, {setose},
         {setaceous}, {spiny}]
     [also: {thorniest}, {thornier}]
Source: WordNet® 2.0