Not yielding in strength, severity, or determination; persistent and unyielding.
From 'un-' plus 'relenting,' where 'relent' comes from Latin 're-' (again) and 'lentus' (slow, pliant). The word originally meant to soften or become less severe, so 'unrelenting' describes something that never softens.
The root 'lentus' also gives us 'lens' (originally lentil-shaped) and 'Lent' (the slow, penitential season)! This family of words all share the concept of gradual change or deliberate slowness, making 'unrelenting' ironically fast-paced in its refusal to slow down.
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