KILLER Synonyms: 201 Similar and Opposite Words

killer 1 of 2

noun

ˈki-lər

Definition of killer

as in headache

a dull, unpleasant, or difficult piece of work weeding out that overgrown garden is going to be a killer

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

as in murderer

a person who kills another person gunned down by hired killers

Synonyms & Similar Words

killer

2 of 2

adjective

as in lethal

likely to cause or capable of causing death killer viruses that claimed millions of lives

Synonyms & Similar Words

Antonyms & Near Antonyms

as in difficult

requiring considerable physical or mental effort a killer exercise program guaranteed to whip you into shape

Synonyms & Similar Words

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of killer

Noun

Detectives worked to identify the killers, but the case eventually went cold. — Milena Malaver, Miami Herald, 16 Oct. 2026 This box set appears to contain EVERYTHING Hank ever recorded along with a killer booklet of photos, etc. — Liza Lentini, SPIN, 16 Oct. 2026 The result is Unhinged, a first-person horror game in which Ava (voiced by Zoë Kravitz) must flee a killer through a powerless apartment building. — Matthew Huff, Time, 15 Oct. 2026 Pamela Voorhees’s appeal was always as an unlikely killer, a devoted mother driven to unspeakable violence by a personal tragedy. — Louis Peitzman, Vulture, 15 Oct. 2026 See All Example Sentences for killer

Recent Examples of Synonyms for killer

Noun

The biggest headache for Thune was the Save America Act, a voter ID bill that lacked a strategy to become law in the Senate.

— semafor.com, semafor.com, 16 Oct. 2026
In Meta’s case, creepy video-recording incidents and privacy-light tampering have caused severe headaches for the company.

— Jibin Joseph, PC Magazine, 16 Oct. 2026

Definition of headache

Adjective

The problem, Snegovaya said, is that achieving military autonomy for Europe and Ukraine is extremely difficult in the short term, and Europe has been slow to develop the necessary capabilities.

— Elsa Ohlen, CNBC, 17 Oct. 2026
Past changes have pushed the glacier into a retreat that may be difficult to reverse, while new modeling suggests scientists may have underestimated how warm seawater reaches beneath it.

— Kaif Shaikh, Interesting Engineering, 17 Oct. 2026

Definition of difficult

Noun

Today in the age of AI, the threats are not just from a lone assassin's bullet but autonomous attack drones.

— Norah O'Donnell, CBS News, 11 Oct. 2026
Based on Nick Harkaway’s novel The Price You Pay, the show follows Jackie Price, a former drug queenpin hunted by seven elite assassins.

— Abbey White, HollywoodReporter, 10 Oct. 2026

Definition of assassin

Adjective

Measles usually kills two or three people in every 1,000 cases, the WHO says, but the disease can be more deadly in poorer nations because of factors such as malnutrition.

— Arkansas Online, Arkansas Online, 18 Oct. 2026
The deadly fire erupted Saturday at Canadian Forces Base Wainwright, where fierce winds fueled flames that spread beyond the installation and into surrounding rural areas.

— Stephen Sorace, FOXNews.com, 18 Oct. 2026

Definition of deadly

Adjective

As Hispanic Heritage Month continues, one musician at Philadelphia's Curtis Institute of Music is challenging expectations about classical music and the harp.

— Madeleine Wright, CBS News, 16 Oct. 2026
Naomi Ackie, who plays the scientist charged with Hagen’s experimental procedure, praised how her co-star shouldered what was a very challenging role.

— Chris Gardner, HollywoodReporter, 16 Oct. 2026