Definition of "borehole" [borehole]

• A hole that is drilled into the earth, as in exploratory well drilling or in building construction. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "A borehole is a small diameter hole drilled from the land surface to collecting soil samples."
• "It would be the first mining project in Minnesota to use something called borehole extraction."
• "A listening device is due to be lowered down a borehole, which is being drilled."