A: According to one version of a popular folk etymology, an Alaskan “sourdough” is someone who is sour on Alaska but doesn’t have the dough to go somewhere else.

The truth is more prosaic. “Sourdough” came to denote a veteran inhabitant and especially an old-time prospector of Alaska or northwestern Canada many years ago. During the Yukon gold rush of the late 19th century, sourdough bread was a staple in the prospectors’ camps, and the prospectors themselves became known as sourdoughs. Eventually, anyone who had spent a significant amount of time in Alaska or northwestern Canada could be called a sourdough.

The examples of “sourdough” you described are attributive uses, where the noun is used like an adjective to modify another noun. Longtime Alaskan residents naturally tend to feel that sourdoughs have certain qualities, such as wit and spunk, that are lacking in “cheechakos,” that is, in newcomers to Alaska or the Yukon. (“Cheechako” is a word in Chinook Jargon that literally means “newcomer.”)

You can find out more about sourdoughs and cheechakos in the works of Jack London and Robert W. Service.

Q Why are psychiatrists called “headshrinkers”? – P.P., Ft. Lauderdale, Fla.

A: “Headshrinker” as a slang term for “psychiatrist” appears to have originated as Hollywood jargon in the 1940s.

Various theories have arisen as to just what the original, unknown user had in mind. Here are a few: The word is meant to suggest “shrinking or deflating delusions of grandeur” or shrinking or lessening problems in a patient’s “worry-bloated” head; the word is a reflection of “considerable unconscious hostility” toward mental health professionals; the word, like the similarly used “witch doctor,” simply implies that a psychiatrist is a practitioner with powers beyond our understanding.

A more gruesome theory is that the originator was thinking of the way psychiatrists figuratively, like headshrinkers literally, get “inside” one’s head. (Without going into too many gory details, we can tell you that headshrinking does involve some cutting into the skull.)

That “headshrinker” acquired this new, slang sense back in the mid-40s isn’t so surprising when you realize that headshrinking, as practiced by the Jivaro people of the Amazon, was something that was in the news at the time. A 1945 anthropological text expressed concern that “shrunken heads made by the Jivaro Indians have received undue publicity in the United States.”

Not surprisingly, this minor obsession spawned movies. The 1939 film “Five Came Back” (remade in 1956 as “Back From Eternity”) concerned a plane crash in the Amazon, with some of the victims falling ultimately into the hands of headshrinkers. “Jivaro” in 1954 featured Fernando Lamas and Rhonda Fleming as treasure-hunters risking death in the Amazon.

It was during the mid-50s that the term gained prominence – at first more so on the West Coast than the East. The Jivaro gave up headshrinking some decades ago, so there hasn’t been much concern about literal headshrinkers for quite some time. That may be part of the reason why “headshrinker” was being casually shortened to “shrink” by the 1960s. “Shrink” is now much more common than “headshrinker,” being applied, rather routinely, to psychiatrists, psychoanalysts, psychologists and psychotherapists.

This column was prepared by the editors of Merriam-Webster’s Collegiate Dictionary, Tenth Edition. Readers may send questions to Merriam-Webster’s Wordwatch, P.O. Box 281, 47 Federal St., Springfield, MA 01102.

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