merciless

having or showing a lack of sympathy or tender feelings she is a merciless competitor at board games of any kind Synonyms affectless, callous, case-hardened, cold-blooded, compassionless, desensitized, hard-boiled, hard-hearted, heartless, indurate, inhuman, inhumane, insensate, insensitive, ironhearted, hard, obdurate, pachydermatous, pitiless, remorseless, ruthless, slash-and-burn, soulless, stony (also stoney), stonyhearted, take-no-prisoners, thick-skinned, uncharitable, unfeeling, unmerciful, unsparing, unsympatheticRelated Words boorish, heedless, inconsiderate, thoughtless, uncaring, unfriendly, unloving, unthinking; grim, hard-bitten, harsh, heavy-handed, ironfisted, ironhanded, jackbooted, knock-down, drag-out (or knock-down-and-drag-out), oppressive, rough, rough-and-tumble, severe, sledgehammer, stern, tough, ungentle; abusive, acrimonious, disagreeable, hateful, ill-natured, ill-tempered, malevolent, malicious, mean, rancorous, spiteful, surly, virulent; barbarous, bestial, brutal, brutish, cruel, evil-minded, savage, vicious; austere, cold, frostyNear Antonyms benevolent, benignant, gentle, kind; clement, indulgent, lenient, mild; cordial, friendly, good-natured, good-tempered, gracious; tolerant, understanding; affectionate, fond, lovingAntonyms charitable, compassionate, humane, kindhearted, kindly, merciful, sensitive, softhearted, sympathetic, tender, tenderhearted, warm, warmhearted