Flatten(a.) To reduce to an even surface or one approaching evenness;   to make flat; to level; to make plane.
    
    
    
        Flatten(a.) To throw down; to bring to the ground; to prostrate;   hence, to depress; to deject; to dispirit.
    
    
    
        Flatten(a.) To make vapid or insipid; to render stale.
    
    
    
        Flatten(a.) To lower the pitch of; to cause to sound less sharp; to   let fall from the pitch.
    
    
    
        Flatten(v. i.) To become or grow flat, even, depressed dull, vapid,   spiritless, or depressed below pitch.
    
    
    
        Flattened(imp. & p. p.) of Flatten
    
    
    
        Flattening(p. pr. & vb. n.) of Flatten
    
    
    
    Words within flatteners