I have a friend from Mississippi and I've heard him use this expression sometimes: slicker than snot on a doorknob. What exactly does it mean? (I guess it's something positive but I'm not too sure myself.)
Doorknobs, generally being made of smooth materials such as brass or glass, are somewhat slippery. Snot, also being made of smooth materials, is comparably slippery.
Combine the two and you have quite the traction-less situation.
This is a vivid metaphor known colloquially as a 'redneck expression', like colder than a witch's tit in a brass brassiere or hotter than two rats [redacted] in a wool sock.
For what it's worth, I have always heard it as
slicker than snot on a **glass** doorknob.
I'm inclined to think this expression may be a coinage from Harlan Ellison (sci-fi writer hero of my youth, who moved on to become a successful Hollywood screenwriter). The earliest occurrence of slicker than snot I can find is from his 1972 The other glass teat: further essays of opinion on television. He writes of some particularly abysmal TV shows that they have vanished...
...with no moans of sadness, for they passed through our culture and prime time slicker than snot on a doorknob (or doo-doo through a colander, depending how vomitous you'll allow me to get)
Based on the fact that doo-doo through a colander occurs nowhere else in Google Books, it seems likely to me that Ellison created both expressions there and then, but only the former survived.
Ellison himself is pretty slick with words - among which I'm quite taken with his “The two most common elements in the universe are Hydrogen and stupidity.”
As regards meaning, per Ellison's usage above, it's an alliterative conjunction of (pejorative) slickness with a situation whereby something exceptionally unpleasant turns out to be exactly where you can't avoid coming into contact with it (you have to turn the knob to use the door).
More recent usages often dispense with the "unpleasant" connotation, with the expression being used as a (sometimes even admiring) metaphorical reference to a smooth operator, or simply a literal reference to slipperiness (icy roads, pavements, etc.)
With regard to the earliest confirmed appearance of "snot on a doorknob" in print, I note the expression is mentioned at least as early as the 1960s, including one instance that notes it as having been collected by a folklorist in 1953.
From a footnote in Austin Fife, Folklore: Collected Articles of Austin E. Fife: 1939, 1941, 1960-1967; Book Reviews: 1947-1965 (1967) (also published in Western Folklore [July 1966]) [snippet view] :
- As slick as snot on a doorknob (OCH).
Fife's exposure to the expression seems to have come from a conversation with Opal C. Howell, of Moab, Utah, on July 27, 1953, according to this note from the book (combined snippets):
More Similes from Moab, Utah.—The following similes were recorded at a single sitting from Mrs. Anne S. Chamberlain, 65, and her daughter, Mrs. Opal C. Howell, 25, both of Moab Utah, by Austin E. Fie and Alta S. Fife, July 27, 1953. (Fife Collection I 882, pp. 1–4.) The recital alternated between mother and daughter until one had exhausted the store for the moment; then the other would take over. The present alphabetical arrangement by adjective and verb does not show how preponderant the mother's repertory was, even though the initials ASC and OCH have been added to show respective authorship.
A decade later, Western Folklore, volumes 35–36 (1976[?]) lists an extended version of "snot on a doorknob" as a simile for slick [snippet view]:
- as slick as greased hog snot on a doorknob (1F)
The same source cites the "slicker than" comparative form, as well:
- slicker than snot on a doorknob
Other probable early instances of "snot on a doorknob" appear in nonviewable texts, including Southern Folklore Quarterly, volume 28 (1964), and Leon Harris, Only to God: The Extraordinary Life of Godfrey Lowell Cabot (1967).
One other interesting early instance appears in an unidentified, in Newsweek, volume 82, issues 19–27 (1973) [combined snippets]:
The rest of us suffered brain damage indeed under the salty orthodoxies of the Moral Life. Freakishly, Lee never paid "the price," whatever that is: all the right-blooded Ervins and correctitudinous the contrary, poor Little Old Lee got absolutely everything in life he ever wanted. Because, as my grandfather said, "he was slick as snot on a doorknob."
And from "Is Rio Hondo Slipping Down Hill?" in the [Whittier, California] El Paisano (May 20, 1975):
"The reason Rio is creeping down the hill," says Caskey, "is that the clay soil becomes wet from rain and from watering the lawns."
Caskey said the school is built on soil over bedrock, [W]hen the soil becomes wet, it can become "slicker than snot on a doorknob."
Collections of similes list numerous "slick as a" or "slicker than"comparisons, but do not include "snot on a doorknob" among them.
For example, Richard Thornton, An American Glossary (1962) notes that slick originated as a variant form of sleek in the sense of "smooth, neat, easy; also smoothly, quickly." Thornton notes multiple similes built on slick—"slick as an eel," "slick as oil," "slick as goose-grease," "slick as a candle," and "slick as a whistle"—but not "slick as snot."
Frank Wilstach, Dictionary of Similes (1924) lists "slick as a ribbon," ""slick as greased lightning," "slick as sin," "slick as a whistle," "slick as grease," "slick as a butterfly's wing," and "slick as soap grease"—but not "slick as snot on a doorknob [or elsewhere]."
Ellen Massey, Bittersweet Country (1978) doe list the expression, along with another vivid simile [snippet view]:
Slick as a wax snake on a marble floor.
Slick as snot on a doorknob.
Robert Hendrickson, The Facts on File Dictionary of American Regionalisms (2000) mentions "slick as a school-marm's leg" (from New England), "slicker'n a smelt" (also from New England), and "slick as a peeled onion" (from Appalachia), but no snot-related similes.
Although Harlan Ellison's use of the expression "slicker than snot on a doorknob" in The Other Glass Teat: Further Essays of Opinion on Television (1972) is one of the earliest published instances of the simile in that form, "slick as snot on a doorknob" is noted in two unrelated folklore glossaries from the 1960s, one of which cites its use by a speaker in Utah in 1953. The phrase thus seems likely to have originated in the U.S. South or West no later than the very early 1950s.
Nevertheless, growing up in southeast Texas in the 1960s, I never heard anyone use the expression. My impression is that it is not recognized and used as a standard simile in much of the United States, even today.
To me, it means that your hand will come off of said doorknob VERY FAST! Based on the idea that if you grab onto a doorknob that has something unknown on it, your first instinct is to let go. But once you realize that said substance is SNOT, your entire mind and body will be completely consumed with the visceral commitmentment to remove your hand!! Perhaps at speed approaching the speed of sound.
And anybody with a whit of imagination can relate, and will unconsciously wince at the thought of sticking their own hand on a similar doorknob.
The connotations of slick in US usage are broader than in British usage. In the USA, slick can mean both physically slippery ("Be careful! The roads are very slick this morning!") and metaphorically slippery ("His answer was too slick for her liking") or metaphorically polished ("She delivered a very slick presentation at the conference"); British usage does not generally imply physical slipperiness.
It is not apparent from the OP's question whether the referent is a person or a physical object.
For me, describing a person as slicker than snot on a doorknob strongly suggests that they are given to sophistry, equivocation, evasiveness or the deceitful manipulation of appearances; they are certainly not to be trusted.
A similarly described physical object (e.g. a road surface or knife handle) is extremely slippery and lacking in grippability, and may also be unpleasant to touch for either physical or psychological reasons.
It's a colourful expression, but a pretty vulgar one. In other words, it's ideal for teenagers who want to piss off their parents.