spine

B2 · Upper Intermediate Countable noun

n. the narrow part of a book cover that faces out when the book is on a shelf.

n. the part of a book's binding that connects the front and back covers, usually displaying the title and author.

日本語:背※

“The title was printed in gold letters on the spine of the old book.”

“Years of exposure to direct sunlight had caused the leather on the book's spine to crack and the gilt lettering to fade.”

C1 · Advanced Countable noun Science Technical

n. a sharp, hard point on an animal or plant, like on a cactus or a porcupine.

n. a rigid, pointed outgrowth or needle-like structure on a plant or animal, often serving a defensive function.

日本語:棘※

“The cactus is covered in sharp spines to protect it from hungry animals.”

“The biologist noted that the fish used its dorsal spines as a primary defense mechanism against larger predators in the reef.”

C2 · Proficiency Countable noun Science Technical

n. a long, thin part that forms the center or support of something.

n. a central feature or ridge that provides structural integrity or acts as a primary axis for a larger formation.

“The mountain spine stretched across the horizon for miles.”

“The volcanic spine, a vertical mass of hardened lava, remained standing long after the softer surrounding rock had eroded away.”