The most challenging aspect of “Camp: Notes on Fashion,” the spring exhibition at the Metropolitan Museum of Art’s Costume Institute, will probably be getting folks comfortable with the idea that a single concept can have multiple, fluid, imprecise definitions. In an age of black and white, good or bad, either-or, camp is about the way in which contradictions and tensions coexist.

Camp is a noun, adjective and verb. It’s exaggeration and artifice. It’s playful and childlike. But it has also been subversive, powerful and political. Camp is rooted in the grand gesture, yet it’s terribly nuanced. Drag is the apotheosis of camp. John Waters is its cinematic guru. Cher is one of its most mainstream practitioners. Billy Porter, on the red carpet at least, has turned it into church.

There’s only one camp and it’s gay, says Moe Myer, editor of “The Politics and Poetics of Camp.” Camp is a stereotype, say its detractors. Camp is irony, say academics.

Camp is so many things that the author Susan Sontag, in an effort to explain it in her “Notes on ‘Camp’ ” from 1964, offers 58 bullet points on it. Her essay serves as the foundational document for the exhibition, which runs through Sept. 8.

Camp “is one way of seeing the world as an aesthetic phenomenon. That way, the way of camp, is not in terms of beauty, but in terms of the degree of artifice, of stylization,” Sontag wrote.

In other words, camp is extra.

It’s self-presentation that honors the importance of personal style — not just in what one wears, but also in how one wears it. At Monday evening’s red carpet gala, which opened the exhibition, Lady Gaga walked in wearing a billowing fuchsia opera coat with a train that practically filled the entire arrival tent. In front of photographers and with the help of designer Brandon Maxwell, she slipped out of ensemble number one to reveal a black gown with a bustle, and underneath that a bright pink slinky column and finally a sparkly bra and panties. Maxwell’s designs weren’t especially camp — except for the starter coat that was the size of a parachute. But Gaga’s high-fashion striptease, with its sweeping gestures and self-conscious gloriousness, certainly was.

If avant-garde fashion thoughtfully attempts to reinvent the coat through experiments in cut and construction, camp is content to pull out an old parka, cover it with a hundred stuffed teddy bears and call it spectacular. Feathers and sequins are camp’s raw materials. Comfort is beside the point.

Camp is not costume, although costumes can certainly be camp. So many gala guests failed to make this distinction. Katy Perry’s chandelier dress was arguably a costume, even though it was designed by Jeremy Scott for Moschino. His entire collected oeuvre — at Moschino and at his own label — is the epitome of camp and features prominently in the exhibit. Camp should have a gloss of high glamour even though it may be undergirded by mass culture. Perry’s chandelier was a feat of engineering rather than delicious camp. Camp does not have to make you laugh, but it should make you want to shout up to sweet Jesus: “Fabulous!”

The exhibition, underwritten by Gucci, captures the extravagance inherent in camp with garments bedecked in feathers and crystals. There are dresses by Japanese designer Tomo Koizumi — who made his New York Fashion Week debut in February — that look like sculptural forms carved out of a mound of multicolored tulle. The contrarian aesthetic of Dutch duo Viktor & Rolf comes through in their upside-down satin dress with its hemline mimicking a strapless bodice. Also included is the infamous swan dress by Marjan Pejoski that Björk work to the Oscars in 2001, a Tiffany jewelry sack-as-dress by Vaquera and the lush, everything-but-the-kitchen-sink luxury of Gucci’s Alessandro Michele.

There are sparkling costumes worn by Cher and Liberace, as well as a float of a dress by Scott that looks like a human-size TV dinner — featuring meatloaf as the main course. Of the contemporary designers included, most are men. Women, perhaps, are less enamored of camp. Or, they are simply underrepresented — as is often the case. The outré expressions of style from the realm of rap are also missing. Is that a kind of camp, or is it worn without the requisite irony to make it so?

The exhibition’s expressions of humor and joy are sure to delight the many visitors who now regularly flock to the Met’s annual Costume Institute shows and turn them into blockbusters. Last year’s “Heavenly Bodies: Fashion and the Catholic Imagination” attracted almost 1.7 million visitors, making it the most attended show in the entire museum’s history, topping the previous record-holder, 1978’s “Treasures of Tutankhamun.” Fashion speaks to the imagination, but it also provides an accessible starting point for conversations about broader, more complicated cultural concerns.

“Camp” is much smaller than “Heavenly Bodies,” and the objects don’t dazzle the eye the way the jewel-bedecked artifacts on loan from the Vatican Museum did. But beyond the chutzpah of Balenciaga’s platform Crocs and the frilliness of Anna Sui baby-doll dresses, there’s a deeply affecting melancholy that permeates the largest of the galleries. It’s heightened by the audio of “Over the Rainbow,” by a raspy-voiced Judy Garland — a pitch-perfect camp icon worn down by age and addiction.

An enormous part of camp comes out of the self-creation and defiance of the gay community. Camp was heavy artillery flamboyance; it was armor and, of course, pleasure.

“It was a way of rebuffing straight society,” says exhibition curator Andrew Bolton during a preview. It was a middle finger to cultural expectations. You see it in the exhibition in Burberry’s floor-sweeping rainbow cape, in Palomo Spain’s gender-fluid, filmy wedding ensemble, in the Jean-Paul Gaultier sailor ensemble with its little white hat, striped sweater and navy sequined pants. “The political aspect of camp was very much embraced. [An older] generation did so consciously,” he says. “The young generation, it’s more unconscious.”

Today, camp may mostly be an expression of fun, but it’s hard not to consider the difficult route to getting to that freedom. To look at a Thom Browne black tuxedo with a white wedding dress affixed to its back sets your mind spinning through the history of same-sex marriage and LGBTQ rights.

“Camp is the heroism of people not called upon to be heroes,” reads a line of wall text from writer Philip Core.

The exhibition adeptly shows that camp has been present in the culture for centuries, whether in the posture of 17th-century paintings or the preening of 20th-century social swans. Once you’ve looked at a Caravaggio through the lens of camp, it’s impossible to unsee the irony and visual excess. A purple Cristobal Balenciaga bubble dress from 1961 has much in common with a purple-feather Moschino dress adorned with a swarm of butterflies from 2018.

If there is a strand of camp history that goes missing in the exhibition, it’s the connection to black gay culture. That relationship was made plain during the gala arrivals by Porter, who was dressed as an Egyptian god and was borne down the red carpet on a litter carried by six shirtless men. Lena Waithe wore a Pyer Moss pantsuit emblazoned with “Black Drag Queens Inventend Camp.” The (mis)spelling was intentional: for emphasis, end of story.

Camp is language that has evolved over time but that remains true to its fundamentals. “What was subversive and political has lost its edge,” Bolton says of camp. But its philosophy of fabulousness continues to thrive in the work of contemporary designers, exhibitionists and aesthetes, as well as those who want to — or need to — stand up to rules and traditions.

Camp: Notes on Fashion Through Sept. 8 at the Metropolitan Museum of Art, New York.