spiny

American  

[spahy-nee] / ˈspaɪ ni /

adjective

spinier, spiniest

1. abounding in or having spines; thorny, as a plant.

2. covered with or having sharp-pointed processes, as an animal.

3. in the form of a spine; resembling a spine; spinelike.

4. troublesome or difficult to handle; thorny.

   a spiny problem.

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spiny British  

/ ˈspaɪnɪ /

adjective

1. (of animals) having or covered with quills or spines

2. (of plants) covered with spines; thorny

3. troublesome to handle; puzzling

4. shaped like a spine

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Other Word Forms

Derived Forms

• spininess
  noun
• nonspiny
  adjective

Etymology

Origin of spiny

First recorded in 1580–90; spine + -y ¹

Explanation

Spiny things are prickly or barbed, like a porcupine or a cactus. You have to be careful when you pick up something spiny. There are many spiny plants and animals, including roses, fish with spiny fins, sea urchins, and hedgehogs. They're all spiny for the same reason—as a defense against predators. The barbs or thorns themselves are called spines, from the Latin spina, meaning "backbone" and also "thorn or prickle." You can also use spiny figuratively to describe something difficult to deal with: "It was a spiny problem indeed."

Example Sentences

They also found many arthropods -- a family that includes modern-day crabs and insects -- including spiny, stalk-eyed creatures called radiodonts which were the apex predator of the time.

From Barron's • Jan. 28, 2026

British gardens matter more than ever for hedgehogs, according to a study of the secret night life of the spiny mammals.

From BBC • Jan. 19, 2026

Covering four representative species—the great white, the sandbar, the small-spotted catshark and the spiny dogfish—Daniel C. Abel and Sophie A. Maycock deliver breadth without sacrificing depth.

From The Wall Street Journal • Nov. 21, 2025

From tree stumps and rocks, the spiny reptiles basked and watched as wooden fences subdivided the landscape.

From Los Angeles Times • Apr. 25, 2025

Nothing green except the cactus and spiny plants.

From "The Voyage Of The Frog" by Gary Paulsen