in·cu·nab·u·lum (ĭn′kyə-năbyə-ləm, ĭng′-)
n. pl. in·cu·nab·u·la (-lə)
1. A book printed before 1501; an incunable.
2. An artifact of an early period.
[New Latin incūnābulum, from sing. of Latin incūnābula, swaddling clothes, cradle : in-, in; see IN-2 + cūnābula, cradle, infancy (from cūnae, cradle; see kei- in the Appendix of Indo-European roots).]
in′cu·nabu·lar (-lər) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.