hard-nosed

stubborn

Synonyms: astute, bullheaded, hard, hard-boiled, headstrong, intractable, levelheaded, locked in, mulish, obstinate, pertinacious, perverse, pigheaded, practical, pragmatic, rational, realistic, resolute, sensible, shrewd, sober, stand pat, tough, tough-nut, unsentimental, unyielding, willful

Antonyms: easy, easy-going, laid-back, merciful