hollow back

noun Bookbinding.
  1. a paper tube or roll, almost flattened, having one side glued to the back of a book and the other to the inside of the spine.
Related formshol·low-backed, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for hollow-back

hollow-back

noun
  1. pathol the nontechnical name for lordosis Compare hunchback
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

hollow-back in Medicine

hollow back

[hŏlō]
n.
  1. lordosis
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.