ˈspīn noun
( -s )
Etymology: Middle English, thorn, spinal column, from Latin spina thorn, spine, spinal column; akin to Tocharian A spin- hook, Latvian spina twig, switch, Sanskrit sphya flat sword-shaped piece of wood used in sacrifices
1.
a. : spinal column
b. : something resembling a spinal column in appearance, place, or function : something constituting a main strength, central axis, or chief support
the land is flat and marshy before rising to a spine of low hills — Robert Turley
he has … spine and starch, in a country sometimes lacking both — John Gunther
give a spine of significance to his butterfly existence — Tennessee Williams
c. : the backbone of a book
d. : the stiff springy quality desired in arrows
2. : a stiff sharp-pointed plant process (as a modified leaf, leaf part, petiole, or stipule) — compare prickle , thorn
3. : a stiff sharp process of an animal body:
a. : a sharp-pointed protective outgrowth consisting of an enlarged and modified hair of a mammal (as a porcupine or a hedgehog)
b. : one of the processes that cover most parts of the body of a sea urchin, that serve for defense or for locomotion, and that are borne on rounded tubercles to which they are movably articulated
c. : a radiolarian spicule
d. : a spiny fin ray of a fish
e. : any of various processes especially of bones : a spinous process (as of a vertebra or of the ilium) ; specifically : a prominent ridge on the back of the scapula
4. dialect England : sward , turf
5. dialect England : the surface layer or rind of meat
6. : a pointed mass of viscous or solidified lava that occasionally protrudes from the throat of a volcano