According to a bit of whimsy making the rounds at the AFL-CIO chieftains' midwinter escape from the chilly realities of home, George Meany is planning his memoirs. The working title, it was suggested, should be "The First Hundred Years."

Some union leaders conceded as they met here for the AFL-CIO Executive Council's annual sunshine session that, while they're laughing on the outside, they're beginning to cry a little on the inside.

Frustrated by what they regard as an over-the-hill image and resistance to change and new ideas, they complain that the labor movement is losing ground as it marks time waiting for the 84-year-old Meany to step down.

But most claim, for the record at least, that the malaise is exaggerated by outside critics and a few inside ones. While acknowledging some troubles, they blame them largely on a conservative drift in the country as a whole and other forces beyond their control.

And some of the critcis say the problems run far deeper than Meany's age, raising questions about how well unions address the concerns of today's workers -- about the future of the labor movement itself.

Interestingly, there was enough uncertainty about what workers really think that talk developed at one Council session last week about commissioning a poll to find out.

But attention focuses on Meany because his larger-than-life presence is so deeply implanted in the public's mind that he comes to personify the labor movement, even though very few of today's workers are 84-year-old Bronx-born plumbers. And his presence is so strong, so forceful, that it tends to squelch dissent before it starts.

Before the Executive Council convened here last Monday, there were rumors circulating at high levels within the AFL-CIO that this might be Meany's last year at the helm of the federation he forged nearly 25 years ago. But when they surfaced publicy in the form of an ever-so-diplomatic suggestion that he might consider retiring into a "chairman-of-the-board" kind of role, he reacted like a wounded bull.

The AFL-CIO already has a chairman of the board, he retorted, and "here he is." When an old friend greeted him by name shortly afterward, he grinned mischievously and said, "Just call me chairman of the board."

That was about the last anyone heard of the idea.

Those who would like to see Meany soon step down concede that he is a living legend, a powerful "presence" who has given the labor movement unprecedented cohesiveness and an intimidating voice in the arena of political debate, a man whose steel-trap mental powers have somehow resisted the softening of age.

Physically he shows his age: hunched shoulders, parchment skin, a cane for walking and assistance from aides as he descends from a podium. But no one suggests the slightest hint of senility. As Operating Engineers Union President J.C. Turner put it euphemistically the other day, "He seems to be meeting all trains."

The problem, a small but growing band of union leaders suggests, usually privately, is that the labor movement is in a rut that is getting deeper all the time: waning influence on Congress, souring relations with a Democratic administration, organizing difficulties, a flexing of corporate muscle both at the bargaining table and within the political arena, and a gnawing sense that the leadership is out of touch with the troops.

Union membership declined from roughly 24 percent of the labor force in 1960 to just over 20 percent in 1976, and imaginative, aggressive organizing efforts are more of an exception than a rule. Many members, helped up into the middle class by their unions, are voting from their pockets rather than their union cards. Labor's legislative agenda, torn to shreds by the last Congress, has been shorn of any new initiatives and recast in more modest terms. Moreover, the Carter administration acts as though organized labor has no place else to go politically, and AFL-CIO leaders are hard-pressed to prove them wrong. Said one plaintively: "There may be another 'Jimmy-who' out there."

So great is Meany's command within the union movement and the perception of it on the outside, said one Executive Council member, that everything is "on hold" until the succession comes.

"Everything inside and outside is waiting for a change," said another council member, Albert Shanker, president of the American Federation of Teachers.

Council members, the youngest of whom is 43, disagree on whether Meany's age is a problem.

Few put it as bluntly as William W. Winpisinger, president of the International Association of Machinists, who says simply: "He's too goddamn old... We're not organizing 85-year-olds, we're organizing 18-year-olds, and they think his brain is pickled, whether it is or not."

Garment Workers Union President Sol C. Chaikin, who suggested the short-lived "chairman of the board" idea, can conduct the age argument all by himself. "No one would have said to Einstein, 'You can't continue to work because you're too old,' " Chaikin said in a talk with reporters, but the United States is a country that "makes a certain obeisance to youth" and "there is something to be said for the public perception...." He resolved the argument only by suggesting that an emeritus position be made available in case anyone wanted it.

Glenn Watts, president of the Communications Workers of America, has also suggested that Meany should consider retirement, and AL Grospiron, president of the Oil, Chemical and Atomic Workers, says he'll retire at 65 and thinks it's a "good prescription for everyone."

Most of the rest of Meany's 34 colleagues on the council are keeping their own counsel, saying they will tell Meany when and if the time appears to have come. Meanwhile, they rarely, if ever, challenge their patriarch, especially behind the closed doors of their meetings.

A number of them agree that, if the council took a secret-ballot vote now on whether Meany should stay on, a substantial majority would vote yes. If Meany has any plan not to seek a 13th two-year term at the federation's biennial convention in November, he's not sharing it. His heir-apparent, Secretary-Treasurer Lane Kirkland, said last week he expects to be running again for the No. 2 job.

Kirkland, a bright but bland man who reportedly has some independent ideas but rarely shares them widely, is "everyone's second choice," according to one insider who believes his ascension will trigger an explosion of pent-up ambitions, frustrations and personal as well as institutional rival-ries that Meany has kept in check.

Some suggest this may be one reason why Meany, who invested so many years in uniting labor, does not step down. Others suggest more human reasons, including what Chaikin called the "empty, bleak canvas" that retirement might hold out for him, as well as a stubborn distaste for retreating under fire. "The Carter people would love to see him go, and I don't imagine he'd like to give them that pleasure," said a colleague.