[re.lent.less] adj (1592): showing or promising no abatement of severity, intensity, strength, or pace: unrelenting "~ pressure" "a ~ campaign" -- re.lent.less.ly adv -- re.lent.less.ness n
RELENTLESS
Meaning of RELENTLESS in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012