ruthless

adjective

ruth·​less ˈrüth-ləs 

also ˈru̇th-

: having no pity : merciless, cruel

a ruthless tyrant

ruthlessly adverb

ruthlessness noun

Did you know?

If someone can be ruthless, can one also be ruthful?

Ruthless can be defined as "without ruth" or "having no ruth." So what, then, is ruth? The noun ruth, which is now considerably less common than ruthless, means "compassion for the misery of another," "sorrow for one's own faults," or "remorse." And, just as it is possible for one to be without ruth, it is also possible to be full of ruth. The antonym of ruthless is ruthful, meaning "full of ruth" or "tender." Ruthful can also mean "full of sorrow" or "causing sorrow." Ruth can be traced back to the Middle English noun ruthe, itself from ruen, meaning "to rue" or "to feel regret, remorse, or sorrow."

Synonyms of ruthless

• merciless
• stony

Examples of ruthless in a Sentence

The journalist was ruthless in his criticism.

an office supervisor with a ruthless disregard for others' feelings

Recent Examples on the Web

The ruthless county SHEriff has professional-grade acetone running through her veins. — Amanda Whiting, Vulture, 5 Nov. 2026

Why would Trump choose to support Putin in his ruthless efforts in Ukraine? — Tom Jurkowsky, Baltimore Sun, 2 Nov. 2026

The stump itself won’t damage buried water lines, per se, but the roots can be ruthless with pipes. — Steven John, Architectural Digest, 29 Oct. 2026

The Dnieper River town, held by Russian forces, has been cut off and starved by months of ruthless drone and mine warfare. — Fred Weir, Christian Science Monitor, 29 Oct. 2026

Word History

Etymology

Middle English rewthles, routheeles, from rewthe, routhe "pity, ruth" + -les -less

First Known Use

14th century, in the meaning defined above

Rhymes for ruthless

• toothless

Kids Definition

ruthless

adjective

ruth·​less ˈrüth-ləs 

: having no pity : merciless, cruel

ruthlessly adverb

ruthlessness noun