English Reference
adjective

relentless

adj.
US /ɹɪˈɫɛntɫɪs/ UK /ɹɪlˈɛntləs/ re·lent·less

  1. 01 B2 Upper Intermediate

    continuing without stopping or getting weaker, often in an annoying or tiring way.

    unremitting and steady in pace or intensity; often used to describe sounds, weather, or pressure.

    Simple

    The relentless noise from the construction site made it impossible to sleep.

    In context

    The relentless rain throughout the weekend caused significant delays in the outdoor restoration project.

    Usage

    Usually placed before the noun it describes.

  2. 02 C1 Advanced Formal

    refusing to give up or be less strict.

    unyielding or inflexible in purpose, severity, or determination.

    Simple

    The team was relentless in their search for the truth.

    In context

    The prosecutor was relentless in his cross-examination, refusing to let the witness avoid the difficult questions.

    Teacher's tip

    While often negative, this can be used as a compliment for someone's work ethic or determination.

Usage relentless accusations

This summer’s relentless heat has meant that some have been forced to cancel surgeries because operating theatres have become dangerously hot.

The Guardian· 15 Aug 2026

The centre’s director, Dr Karmele Llano Sánchez, said in her latest update that battling the fire had been relentless.

The Guardian· 14 Aug 2026

From relent + -less.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated