Definition of "dowser"

Interestingly enough, John Mullins, the celebrated English dowser, was able to do this experiment using a forked twig, rather than a pendulum. He claimed to be able to locate nothing but water with his dowsing rod.

1996, Richard Webster, Dowsing for Beginners: The Art of Discovering Water, Treasure, Gold, Oil, Artifacts, Llewellyn Worldwide

The instrument a dowser uses is called a dowsing rod, dowsing stick, doodlebug (when used to locate oil), or divining rod. Almost any item can be used for this purpose: a birch twig, a whalebone, and even a hanger.

2002, Michael Shermer, The Skeptic Encyclopedia of Pseudoscience, ABC-CLIO, page 93

Google Cayce and you will find “coolhunter,” and if you look closely you may see it suggested that she is a “sensitive” of some kind, a dowser in the world of global marketing.

2003, William Gibson, Pattern Recognition (Bigend cycle; book 1), New York: G. P. Putnam's Sons, page 2