relentless

قَاسٍ \ austere: (of people) severe, self-controlled and serious: He always has an austere expression, and never smiles. bad, (worse, worst): (of things that are never good) serious; severe: a bad accident; a bad cold. brutal: having no feeling; cruel: a brutal war; a brutal act of violence. callous: (of the skin) hardened and thick. cruel: liking to hurt others; unkind; causing pain: It is cruel to lock up a child. He struck her a cruel blow. fierce: (of people, their actions and feelings) violent: a fierce attack; a fierce hatred. grim: very serious; ready to suffer or to make others suffer; not yielding; merciless: he faced his enemy with a grim smile. hard: firm; not soft: as hard as iron, not gentle; unkind; demanding complete obedience He’s a hard father. He’s hard on his children. harsh: (of people and punishments) hard; cruel. inhuman: cruel; lacking natural human kindness. merciless: showing no mercy. relentless: pitiless. rigid: stiff; not bending unable to bend. ruthless: merciless; pitiless: a ruthless enemy. severe: (of things) bad or violent, causing anxiety; (of people) hard and merciless: a severe illness; a severe judge. stern: severe demanding obedience: stern treatment; a stern father. stringent: (of conditions, rules, etc.) severe; demanding exact fulfilment. tough: not easily cut or torn or broken: tough meat; tough glass. violent: using force; fierce: a violent attack; a violent temper. virulent: very harmful to the health; poisonous; full of hate: a virulent disease; a virulent political speech. \ See Also عنيف، خبيث (خبيث)، جامد (جامد)، عديم الشفقة، صارم (صَارِم)، مؤلم (مُؤْلِم)، شنيع (شنيع)، وحشي (وَحْشِيّ)، غليظ (غليظ)‏