shark

¹ American  

[shahrk] / ʃɑrk /

noun

1. any of a group of elongate elasmobranch, mostly marine fishes, certain species of which are large, voracious, and sometimes dangerous to humans.

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idioms

1. jump the shark, to begin a decline in quality, popularity, relevance, etc., after reaching a peak.

   Some TV shows have jumped the shark once a popular cast member left the show.

shark ² American  

[shahrk] / ʃɑrk /

noun

1. a person who preys greedily on others, as by cheating or usury.

2. Informal. a person who has unusual ability in a particular field.

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verb (used with object)

1. Archaic. to obtain by trickery or fraud; steal.

verb (used without object)

1. Archaic. to live by shifts and stratagems.

shark ¹ British  

/ ʃɑːk /

noun

1. a person who preys on or victimizes others, esp by swindling or extortion

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verb

1. archaic to obtain (something) by cheating or deception

shark ² British  

/ ʃɑːk /

noun

1. any of various usually ferocious selachian fishes, typically marine with a long body, two dorsal fins, rows of sharp teeth, and between five and seven gill slits on each side of the head

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Other Word Forms

• sharklike
  adjective

Etymology

Origin of shark¹

First recorded in 1560–70; origin uncertain

Origin of shark²

1590–1600; < German dialect Schork, variant of Schurke rascal

Explanation

A shark is a large, carnivorous fish — although it's hard to calmly think, "That's just a large fish" when you run into a shark while you're swimming in the ocean. Almost all sharks live in the ocean, and while most of them are predators, the very largest sharks feed on plankton and tiny things like fish eggs. There are over four hundred species of shark, but only four have ever harmed humans; nevertheless, people have been afraid of these large, powerful animals for a long time. This dislike gave rise to the informal meaning of shark, "a person who swindles or preys on others."

Example Sentences

The study -- conducted at the Shark Reef Marine Reserve in Fiji -- found that bull sharks do not simply mix randomly.

From Science Daily • Mar. 17, 2026

Anduril’s sea drone, Ghost Shark External link, is a competing program.

From Barron's • Mar. 11, 2026

According to the world-renowned International Shark Attack File, the 2024 attack on Peter was the first and only shark attack ever recorded in Tobago.

From BBC • Feb. 4, 2026

“The Land Shark shows up when you need him the most,” coach Sean McVay said.

From Los Angeles Times • Jan. 22, 2026

This had given the Ancient Shark an idea.

From "The Wild Robot Protects" by Peter Brown

Related Words

• astute
• cagey
• canny
• crafty
• farsighted
• ingenious
• judicious
• keen
• penetrating
• perceptive
• probing
• prudent
• sensible
• sharp
• slick
• sly
• smart
• wily
• wise