Mort Walker of Beetle Bailey and Hi and Lois fame is also credited with creating a bunch of nonsense words for the shorthand symbols used in Comic Strips. In 1980 he released a book called The Lexicon of Comicana that listed and defined all of these terms. Many of the terms were adopted by other cartoonists, and even incorporated into cartooning how-to books, although those of us outside the industry (or just preferring to not sound crazy) will usually still use expressions like "dust clouds" and "motion lines".
Not all those phenomena are comic-exclusive. Some of these can also be found in cartoons, other media or internationally recognized symbols.
This is a list of some of the more well known ones:
Agitrons: Similar in function to blurgits, longer wiggly lines around something that is shaking or vibrating.
Blurgits: Similar in function to agitrons, parenthesis-shaped symbols used to indicate less intense movement, such as a nudge, shoulders shrugging, or slow walking (in a waist-up shot).
Briffits: Clouds of dust that trail behind fast-moving characters, linger in the spot where a character suddenly dashed out of frame, or appear in clumps when objects or characters collide. Car exhaust can serve as a more realistic version of this.
Dites: Similar to vites, diagonal lines placed across glass surfaces (either reflective or clear) to indicate sheen. In color comics these are sometimes filled in with white, or, in more modern comics, replaced entirely with a semi-transparent airbrushed white line.
Emanata: Lines and symbols that act as visual shorthands of a character's internal state and emotions, such as a Frustrated Overhead Scribble indicating frustration, heart symbols floating above a character's head indicating them falling in love, and lines surrounding a character's head to indicate surprise or shock, etcetera. Several other items on this list, such as plewds, squeans, and solrads, are considered to be forms of Emanata.
Grawlixes: Indicating swearing with non-alphanumeric characters such as stars, angry scribbles, storm clouds (sometimes complete with lightning bolts), swirls, large exclamation points, and skulls. Machine-lettered comics will often just use keyboard characters. Walker identified a number of distinct types based on specific symbols, such as jarns (curved or angled spirals), quimps (astronomical objects), nittles (stars and asterisks) and true grawlixes (scribbles suggesting scrawled writing).
Hites: Horizontal lines that trail behind fast-moving characters to indicate motion. Usually come in pairs. A variation is up-hites, which are vertical and appear above a falling object or character.
Indotherm: Squiggly lines placed over an object to indicate radiant heat. May also appear above the head of an extremely irritated character.
Lucaflects: Thinly-outlined shapes placed on shiny surfaces to indicate reflectiveness. Often takes the form of a four-paneled window, most commonly on TV screens.
Plewds: Drops of sweat emanating from the character's head to indicate nervousness, stress, or working hard.
Solrads: Lines proceeding from a light source.
Squeans: Bubbles and open asterisks (popped bubbles) that appear over a drunk or sick character's head. See also Alcohol Hic.
Vites: Similar to dites, vertical lines placed on bodies of ice to indicate reflectiveness. Often placed directly under a character and filled with whatever color the character is.
Waftarons: Squiggly solid shapes that taper to a point on both ends, used to indicate strong odors, either positive or negative (the former typically filled with white, the latter with a sickly green). Warm food items (like a pie cooling on the windowsill) will typically have small wafterons in place of indotherms to indicate both heat and odor.
In a Bloom County Sunday strip for August 5, 1987, Berke Breathed came up with alternate names for some of the above terms, still popular today. In the order they appeared:
Boozles: See Squeans. In the comic, they're "root boozles" since Milo isn't old enough to drink.
Cranial Smoke: See second definition of Indotherm ("Carcinogenic if inhaled").
Moovles: See Blurgits.
Poofles: See Briffits.
Shooples: Reverse zipples, or the standard up-hites.
Surprisles: See Emanata.
Sweatles: See Plewds.
Swivles: A curved version of hites used to indicate turning.
Zipples: Up-hites indicating upward motion.
Breathed also coined the term Bulble for the good ol' Idea Bulb and noted that Stars indicate severe pain.
Analogous visual shorthands developed separately in Manga, and consequently also Anime, some of which are categorized under Japanese Visual Arts Tropes and its subindex Manga Effects. The Sweat Drop is broadly similar to plewds, although usually with a single large downward drop used to communicate exasperation as well as embarrassment. Cross-Popping Veins, the Visible Sigh, and the more heavily stylized forms of the Corner of Woe are also common forms of emanata.
Examples:
Advertising
- Sexual Violence with the Birds and the Bees: In one poster
◊, the girl that Zach tries to get with has bubbles over her head, indicating drunkenness.
Comic Books
- The Loneliness of the Long-Distance Cartoonist: Invoked. To demonstrate his profession for his daughter's class, Adrian draws a man running. He draws loops around the man's head (plewds) and the kids pick up that the man is sweaty. He draws a poofy shape followed by lines (briffits) intending to show the man's speed, but the kids think he farted.
Fan Works
- Hazbin Hotel — All I Want For Christmas Is You: When Niffty, Angel, and Husk dash off to tackle their assigned festivity preparations, they leave dust clouds in the air behind them.
Literature
- How to Read Nancy: Acknowledged in the "Motion Lines" lesson, which shows how even a few understated squibbles of linework can be subtly used to indicate motion, such as Sluggo advancing towards Nancy in the third panel.
Tabletop Games
- The Fluffy Folio: The Boozle is named after the Bloom County term for cartoony drunk bubbles, and resembles it by being a floating, bubble-like ooze that releases an intoxicating gas when popped.
Video Games
- Dr. Robotnik's Mean Bean Machine: Plewds appear when enemies are close to losing. When they're in really big trouble, they start flashing as well. It's really disheartening to lose after this.
- Just Dance: Pictograms use "blurgits" to indicate small movements like wiggling, foot stomping and head turning. A cartoonish explosion version represents stronger, snappier moves, like punching the air.
- Persona 4: The game's favored way of visually conveying emotions outside of anime cutscenes. There's a wide variety of symbols that can appear over characters' heads. Yosuke lampshades this in Golden when referring to the protagonist not being able to explain that Marie is otherworldly, as he jokes that if he did, "the question-mark above his head would be seen from orbit".
Webcomics
- Newheimburg: These visual shorthands come up a number of times throughout Newheimburg. Wafterons are used as a regular motif for Jack's emotional state. Plewds and blurgits are often used to indicate nervousness and movement as well.
- Runaway to the Stars: One set of reader questions, where Gillie accidentally ruins one of Idrisah's attempts at being romantic, uses a mixture of American and Japanese symbols, with Gillie emitting worried plewds while Idrisah mopes under the vertical hatching of a highly stylized Corner of Woe.
Western Animation
- My Little Pony: Friendship Is Magic: In "Suited for Success", Rarity emits flying sweat drops from the head when noticing Opalescence stranded in a tree.