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."

Definitions of shark
  1. noun
    any of numerous elongate mostly marine carnivorous fishes with heterocercal caudal fins and tough skin covered with small toothlike scales
    see moresee less
    show 30 types...
    hide 30 types...
    Hexanchus griseus, cow shark, six-gilled shark
    large primitive shark widely distributed in warm seas
    mackerel shark
    fierce pelagic and oceanic sharks
    Alopius vulpinus, fox shark, thrasher, thresher, thresher shark
    large pelagic shark of warm seas with a whiplike tail used to round up small fish on which to feed
    Orectolobus barbatus, carpet shark
    shark of the western Pacific with flattened body and mottled skin
    Ginglymostoma cirratum, nurse shark
    small bottom-dwelling shark of warm shallow waters on both coasts of North America and South America and from southeast Asia to Australia
    Carcharias taurus, Odontaspis taurus, sand shark, sand tiger
    shallow-water shark with sharp jagged teeth found on both sides of Atlantic; sometimes dangerous to swimmers
    Rhincodon typus, whale shark
    large spotted shark of warm surface waters worldwide; resembles a whale and feeds chiefly on plankton
    cat shark
    small bottom-dwelling sharks with cat-like eyes; found along continental slopes
    requiem shark
    any of numerous sharks from small relatively harmless bottom-dwellers to large dangerous oceanic and coastal species
    any of several small sharks
    hammerhead, hammerhead shark
    medium-sized live-bearing shark with eyes at either end of a flattened hammer-shaped head; worldwide in warm waters; can be dangerous
    Squatina squatina, angel shark, angelfish, monkfish
    sharks with broad flat bodies and winglike pectoral fins but that swim the way sharks do
    Lamna nasus, porbeagle
    voracious pointed-nose shark of northern Atlantic and Pacific
    mako, mako shark
    powerful mackerel shark of the Atlantic and Pacific
    Carcharodon carcharias, great white shark, man-eater, man-eating shark, white shark
    large aggressive shark widespread in warm seas; known to attack humans
    Cetorhinus maximus, basking shark
    large harmless plankton-eating northern shark; often swims slowly or floats at the sea surface
    Carcharhinus leucas, bull shark, cub shark
    a most common shark in temperate and tropical coastal waters worldwide; heavy-bodied and dangerous
    Carcharhinus plumbeus, sandbar shark
    most common grey shark along coasts of middle Atlantic states; sluggish and occasionally caught by fishermen
    Carcharhinus limbatus, blacktip shark, sandbar shark
    widely distributed shallow-water shark with fins seemingly dipped in ink
    Carcharinus longimanus, oceanic whitetip shark, white-tipped shark, whitetip shark
    large deep-water shark with white-tipped dorsal fin; worldwide distribution; most dangerous shark
    Carcharhinus obscurus, dusky shark
    relatively slender blue-grey shark; nearly worldwide in tropical and temperate waters
    Negaprion brevirostris, lemon shark
    common shallow-water schooling shark of the Atlantic from North Carolina to Brazil and off west Africa; dangerous
    Prionace glauca, blue shark, great blue shark
    slender cosmopolitan, pelagic shark; blue body shades to white belly; dangerous especially during maritime disasters
    Galeocerdo cuvieri, tiger shark
    large dangerous warm-water shark with striped or spotted body
    Galeorhinus zyopterus, soup-fin, soupfin, soupfin shark
    Pacific shark valued for its fins (used by Chinese in soup) and liver (rich in vitamin A)
    smooth dogfish
    small bottom-dwelling shark found along both Atlantic coasts
    spiny dogfish
    small bottom-dwelling dogfishes
    Sphyrna zygaena, smooth hammerhead
    fished for the hides and vitamin-rich liver
    Sphyrna tudes, smalleye hammerhead
    fished for the hide and vitamin-rich liver
    Sphyrna tiburo, bonnet shark, bonnethead, shovelhead
    small harmless hammerhead having a spade-shaped head; abundant in bays and estuaries
    type of:
    elasmobranch, selachian
    any of numerous fishes of the class Chondrichthyes characterized by a cartilaginous skeleton and placoid scales: sharks; rays; skates
  2. verb
    hunt shark
    see moresee less
    type of:
    catch or try to catch fish or shellfish
  3. noun
    a person who is ruthless and greedy and dishonest
    see moresee less
    loan shark, moneylender, shylock, usurer
    someone who lends money at excessive rates of interest
    type of:
    offender, wrongdoer
    a person who transgresses moral or civil law
  4. noun
    a person who is unusually skilled in certain ways
    see moresee less
    type of:
    expert, pundit
    a person with special knowledge or ability who performs skillfully
  5. verb
    play the shark; act with trickery
    see moresee less
    type of:
    cheat, chisel
    engage in deceitful behavior; practice trickery or fraud
Word Family

Test prep from the experts

Boost your test score with programs developed by’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week