The word relentless means showing no mercy, compassion or pity. It describes someone who is unyielding and persistent in their actions, often to an extreme degree. They are determined and tireless in pursuit of a goal, and will not stop until they achieve it. Relentless people are fierce competitors, driven by a strong sense of purpose and focus on the end result. In short, relentless means being unstoppable in your efforts to reach a particular objective or outcome.