BURRIEST
Scrabble letter values: B3U1R1R1I1E1S1T1 = 10
Definition
BURRIEST is the superlative of BURRY.
adjective BURRY: having or covered with protective barbs or quills or spines or thorns or setae etc..
Synonyms of BURRY: barbed, barbellate, briary, briery, bristled, bristly, burred, prickly