“Mindful” is the buzzword of the moment. But what does it mean? (Victoria Adams Fogg/The Washington Post)

Jon Kabat-Zinn is Mr. Mindful. He’s been mindful since the Johnson administration, for five decades, long before mindfulness was a movement, a mantra, a mayonnaise.

Also: a tea, the motto of a chain of Chicago burger joints, a diet.

Kabat-Zinn, 71, founder and former executive director of the University of Massachusetts Medical School’s Center for Mindfulness in Medicine, Health Care and Society, is widely considered the father of the modern mindfulness movement, a practice derived from Buddhist meditation.

He is invited to speak all over the globe about mindfulness, which he defines as “the awareness that arises by paying attention on purpose in the present moment non-judgmentally.”

So Kabat-Zinn seems the man to ask how “mindful” became the buzzword of the moment, applied to clothing, tea and adult coloring books — mind you, a whole series of adult coloring books. The Epic Burger chain produces “a more mindful burger,” because lettuce, tomato and Epic sauce weren’t enough.

To which Kabat-Zinn responds with a shrug: “It’s a mystery to me.”

Surely, we were veering in this direction. In 2012, Rep. Tim Ryan (D-Ohio) wrote a book advising us to become “A Mindful Nation.” Last year, Parliament recommended that Britain become one, too.

An increasing number of academic studies, nearly 700 in 2015, have examined mindfulness’s positive effect on stress, brain connectivity and chronic medical conditions, according to the American Mindfulness Research Association, which pleases ­Kabat-Zinn.

The ubiquity of the adjective, however, is another matter.

“I don’t feel particularly good about it,” he says. “When something becomes hot in our society, everyone is an expert and wants to commodify it and make money from it.”

Why have we become so mindful now? “Stress in the last 35 years has gone through the roof,” says Kabat-Zinn, who has a doctorate in molecular biology. “We’re multitasking continually, juggling a thousand things. Mindfulness is a way to maintain sanity.”

Haven’t humans always been stressed? The Depression, the plague, the Inquisition, revolutions, beheadings — all stressful.

Perhaps the difference is that we’re aware of the stress, and we’re mindful of the time and sleep lost worrying about the stress. Also, appearances to the contrary, we have time to stress about the stress.

Perhaps our mindful moment can be blamed, like so many of society’s ills, on the smartphone, which makes people — and stress — available at any time. Hence, the need to be more present and calm, and the proliferation of all things mindful.

And, yes, there’s an app for that. Actually, there are plenty.

Tara Healey is the program director for mindfulness-based learning at Harvard Pilgrim Health Care, which has counseled 150 New England businesses and more than 10,000 workers on becoming more mindful.

“I am kind of happy and excited that this word is out there in the culture in a way that it never has been,” she says, “though I so worry about it getting watered down and losing the integrity of the word. It’s everywhere.”

When a word becomes omnipresent, “like any currency, the more you print of it, the less value it has. The word loses meaning,” says Geoffrey Nunberg, a linguist at the University of California at Berkeley’s School of Information. “Mindful is no different from disruption,” he says, citing another word in overdrive. “When everything’s disruptive,” he cautions, “nothing’s disruptive.”

Frequent mentions of mindfulness — slapping the word on every object and practice — don’t make us more mindful. “People have this magical belief in words as if they’re incantations. The more people use it, the less you’re distinguishing yourself from anyone else,” says Nunberg, who views mindfulness as “being present with a whiff of cardamom.”

Pat Croce is energetic, fit, voluble. He made his fortune in sports medicine outlets, served as president of the Philadelphia 76ers (the Allen Iverson years, not the what-are-they-doing-in-the-NBA 76ers), opened a Florida pirate museum and a chain of pirate-themed bars and restaurants. You know, typical résumé.

Now, Croce spends five hours a day on mindfulness. It’s almost his full-time job: meditating, journaling, intentionally breathing, reading, drawing Chinese characters, getting Chinese character tattoos on his wrist.

“For 60 years, I trained my body,” he says. “I never did a frickin’ thing for my mind.”

In February, Croce and his wife, Diane, donated $250,000 to his alma mater, West Chester University in suburban Philadelphia, for the study of mindfulness at the school’s Center for Contemplative Studies.

“It sounds a little ‘woo-woo,’ ” Croce said when he announced the gift, “but truly, we’re all here. We’re all mindful.”

He hopes that the gift will “expand the 18-credit minor. I would like to see mindfulness become one of the core subjects in the college curriculum. Like math.”

Mindfulness means so many things to different people.

It takes Barry Boyce nearly a quarter-hour to define mindfulness — and he’s the editor of Mindful, a website and bimonthly magazine dedicated to the subject.

“The range of interpretations is huge,” he says. “We’re pretty open about letting people discover for themselves what mindfulness means. We’re just talking mindfulness here. I haven’t even gotten to defining mindful.”

But he is not a “mindful” minder. “I don’t care. I don’t own the English language,” he says. “My job is that we keep giving a meaning for people that is meaningful in a particular context in their lives.”

He notes that “there are some people who think it’s woo-woo” — there’s that technical term again — “but it doesn’t have to be woo-woo.”

Kabat-Zinn, Mr. Mindful, is “resigned” to mindful burgers and tea, “the ubiquity being an inevitable side effect of something as important as mindfulness,” he said. “In a year or two, the fad element will blow over and people will be on to the next new thing.”

Meanwhile, you can find Mindful magazine at Whole Foods, along with the Earth Balance Mindful Mayo — original, organic and olive oil.