21 possible answers to
Answers with 3 characters: ILL Answers with 4 characters: DOUR GRIM Answers with 5 characters: ACERB ACRID CRUEL RASPY ROUGH STARK STERN Answers with 6 characters: BRUTAL COARSE SEVERE STRICT UNKIND Answers with 7 characters: ACERBIC SQUAWKY Answers with 8 characters: RIGOROUS STRIDENT Answers with 10 characters: ASTRINGENT RELENTLESS