Definition of "spelunker" [spelunker]

• One who explores caves chiefly as a hobby; a caver. (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.

• "The term "spelunker" was abandoned sometime in the late 1950s."
• "Among serious cavers, "spelunker" has come to mean "person who goes underground without the proper equipment or training"."
• "Never, ever, have I heard anyone speak of himself as a "spelunker," and the thought that someone might be about to spelunk is droll."