borehole definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a hole drilled in the earth to explore for or release oil, gas, water, etc. or to study the crust of the earth
borehole definition by American Heritage Dictionary
A hole that is drilled into the earth, as in exploratory well drilling or in building construction.