# spine

Pronunciation: US say "SPYN" /spaɪn/; UK

## Noun

1. A series of bones running down the back from the head to the pelvis in humans, or to the tail in animals, enclosing the spinal cord and supporting the body.
   - Simple: The row of small bones running down the middle of the back, from the head to the hips.
   - _Years of poor posture had noticeably curved his spine._
   - _In most fish, the spine extends all the way to the tail._
2. The narrow bound edge of a book that holds the pages together, facing outward on a shelf and usually showing the title and author.
   - Simple: The narrow back edge of a book that you see when it sits on a shelf.
   - _The library glued a fresh call number onto the spine of every volume._
   - _Gold lettering ran down the spine of the leather-bound edition._
3. Courage and firmness of character; the willingness to assert oneself and stand firm under pressure.
   - Simple: The courage to stand up for yourself and not give in to others.
   - _The committee lacked the spine to challenge a popular but reckless decision._
   - _He showed real spine in standing up to the bullies._
4. A pointed, fairly rigid projection or needlelike structure on an animal, shell, mushroom, or plant.
   - Simple: A sharp, stiff point that grows on some plants or animals, like a thorn or a quill.
   - _Each spine on the sea urchin can move independently._
   - _The plant defends itself with rows of stiff spines along its stem._
5. A ridge or long central structure resembling a backbone, from which other structures branch out.
   - Simple: A long ridge or central part that other things branch out from.
   - _A narrow spine of hills divides the two valleys._
   - _The new highway became the spine of the region's transport network._
6. The central part that supports or holds together a whole; the core.
   - Simple: The main part that holds everything else together.
   - _The manufacturing sector remained the spine of the local economy._
   - _A dedicated core of engineers formed the spine of the research effort._
7. Ellipsis of dendritic spine. — Ellipsis of dendritic spine.
   - Simple: Short for dendritic spine. Use it for the tiny signal-receiving bumps on a nerve cell.
   - _The neuron's dendrites were dotted with thousands of tiny spines._
   - _A single spine can strengthen or weaken depending on neural activity._
8. A tall mass of thick, slow-moving lava forced up out of a volcano.
   - Simple: A tall column of thick lava pushed up out of a volcano.
   - _Geologists watched a spine grow from the dome over several weeks._
   - _The famous spine on Mount Pelée collapsed not long after it formed._
9. The stiffness of an arrow, or the degree to which its shaft bends when shot.
   - Simple: How stiff an arrow is, and how much it bends when you shoot it.
   - _The archer chose shafts with a stiffer spine for the heavier bow._
   - _Mismatched spine can send an arrow veering off target._
10. A linear payscale used by some large organizations, with set points that allow flexibility for local and specific conditions.
   - Simple: A pay system used by some big organizations, with set steps for wages.
   - _Teachers progress along the spine as they gain years of experience._
   - _The college reviewed its salary spine to stay competitive with nearby employers._
11. The heartwood of a tree: the dense, older wood at the center of the trunk.
   - Simple: The hard, dead wood at the center of a tree trunk.
   - _Furniture makers value the spine of mature walnut for its strength and color._
   - _The tree's spine remained sound even as the outer layers decayed._

## Origin

This word came into late Middle English as spyne, from Old French espine (modern French épine), or from its source, Latin spīna, meaning a thorn, a prickle or spine, and the backbone. It is a doublet of spina.

Source: DictionaryAI, https://dictionaryai.com/define/spine (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).