noun
    
    plural spines
    
    [count] :the row of connected bones down the middle of the back :backbone
    
    
    
    [count] :a sharp, pointed part on an animal or plant
    
    
    
    
    
    [noncount] informal :courage or strength of character
    
    
    
    [count] :the part of a book to which the pages are attached
    
    
    
    A book's spine often has the title and author's name printed on it.
    
    up/down your spine
    
    If something sends a chill/shiver up/down your spine or if a chill/shiver runs up/down your spine, you become frightened, thrilled, etc.