drillstock

drill·stock

 (drĭl′stŏk′)
n.
The part of a drilling tool or machine that holds the shank of a drill or bit.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

drillstock

(ˈdrɪlˌstɒk)
n
(Tools) the part of a machine tool that holds the shank of a drill or bit; chuck
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014