とげとげしい (translations)→ acrimonious harsh impatient pointed sharply stinging
苦い (translations)→ acrid bad bitterness dour unpleasant
激しい (translations)→ acute agonies bitter brisk considerable crushed desperate fiercely great heatedly heavily hot impetuous intemperate intense intensity manic passionate pitch raucous severe slashing stormy terrible vehemence violent wrenching
厳しい (translations)→ adamantine astringent awful difficult firm grim hard hard-time heavy hurt implacable maximum monastic peppery precarious restrain rigorous rocky sharp stern sternly strict torrid trying
渋い (translations)→ grimly sour subdued
辛辣な (translations)→ biting corrosive cutting mercilessly mordant piquant relentless tacky ungenerous vitriolic waspish