Dear Word Detective: I'm in the midst of an argument with a friend over the expression "spittin' image," meaning look-alike. He insists that the expression is "splitting image." Which of us is correct? What is the origin of this expression? -- Linda, via the internet.
You are correct, although your friend's attempt to make "spittin' image" make more sense as "splitting image" (as if one person had split into two) merits an honorable mention. Your friend's version, incidentally, is a good example of a process known as "folk etymology," whereby an unfamiliar or seemingly nonsensical phrase, often very old, is altered slightly to make it more understandable in modern terms.
But the phrase is definitely "spitting image" or "spittin' image," meaning "exact likeness" and it's based on an earlier form, "spit and image," which first appeared around 1859 Just where the phrase came from and exactly what it means, however, is hotly debated in etymological circles.
Most authorities accept the "spit" element of the phrase at face value, and maintain that it is a remarkably inelegant metaphor for similarity: "just as if one person were spit out of another's mouth." A similar saying in French, "C'est son pere tout crache" ("He is his father's spit and image"), lends support to this theory, as do earlier English sayings with the same meaning, such as "the very spit of," which appeared around 1825.
The late poet and etymologist John Ciardi, however, maintained that "black magic" lay at the root of the phrase. Armed with a sample of someone's saliva ("spit") and a doll made to resemble the person ("image"), goes the theory, a sorcerer could cast all sorts of evil spells on the hapless victim.
Yet another theory regards "spit" as a shortened form of "spirit," but there is no real evidence for this, and it sounds to me like another "folk etymology" effort to make a very weird phrase slightly less weird.