It's a leotard, it's long johns, it's a bodysuit.

Whatever you call it, the white stretch one-piece garb that tennis player Anne White wore at Wimbledon Thursday was banned for future play in that terribly proper English tournament. And it didn't score well with stylish tennis players here, either.

"I'd be so conscious of what I was showing I wouldn't be able to concentrate on the ball," said Nina Auchincloss Straight. She was exercising in an Irish knit sweater and white slacks at Elizabeth Arden yesterday.

She understands well the appeal of stretch garments for riding, as in dressage, as well as for dance. "But in tennis you want even more freedom," said Straight, who describes her tennis level as "never not been defeated."

"Visually the idea of the stretch one-piece suit is a turnoff," she insisted. "I just don't see it. Can you imagine 'Les Sylphides' in pleated skirts and woolly socks? Would you be inspired? It goes both ways. Costume is supposed to put you in the mood."

The problem isn't mood but temperature for Lavinia (Vin) Lemon, an interior designer and tournament tennis player "among the 35 and older group," she added quickly. "I think [such an outfit] would be horribly hot. In swimming, when your legs are going against the water, or in biking, when you are going against the wind, that's another matter.

"In tennis you want to be comfortable -- and the best way is for your legs to be free," said Lemon, who likes the comfort of a simple shirt and shorts.

According to Roberto Muller, chief executive officer of Pony, Inc., manufacturers of athletic and related leisure apparel and shoes, it was Anne White's idea to adapt the Lycra spandex fabric used in cycling, fitness and aerobics garments for tennis. "She wears our products under contract, and it was her idea to adapt this look to tennis."

Last week it was shown to buyers as part of the company's Perfect 10 Collection for spring 1986. Store buyers were surprised and skeptical, but Muller expects it to catch on.

At least with some players. "As in any fashion style trend, some can wear it better than others," he said.

Muller compares it to the stretch suit that ice-skater Eric Heiden first wore in the winter Olympics in 1980. "Everyone said it would be a product of that sport, but then it was adapted for skiing. Now it's used in snow skiing -- not only racing but others, recreational skiing -- exercise and fitness. It is the largest segment of fitness wear. It gives you flexibility, mobility. It's like wearing another skin, a second skin.

"A lot of young girls out there who like to play will find it is going to make them look good."

Muller is not surprised that the item, called Perfect 10 White, started first in the women's line. "In any real forward fashion, the ladies tend to be more innovative and creative. It is their prerogative. Besides," he added, "a woman's body is far more beautiful to look at than a male's body. You would have to be in fantastic shape as a man."

Michael Blumenfeld, president of the Texas-based Tennis Lady and Arthur Ashe and Friends retail shops, agrees that the market for the white stretch tennis suit is limited. "It's attractive, but you have to be built like Anne White is built to wear it. And the rest of the world is not."

The reality, he said, "is that a more mature age group is playing the sport."

Pauline Betz Addie, who won at Wimbledon in 1946, is delighted about the stir Anne White's get-up has caused. "We were obedient robots in my day, went ahead and were polite to the referees, did what we were told . . . for nothing," she said with a laugh.

A former U.S. champion who is director of the Sidwell Friends Tennis Camp, Addie finds most new tennis clothes attractive, "much better than our boring mundane attire." As for the jumpsuit, she said, "I can't imagine playing in one, but I'd have to try it on to see."

Allie Ritzenberg, a senior world champion who runs the St. Alban's Tennis Club, is skeptical about a major deviation from traditional tennis gear. "I can see where stretch fabrics could keep muscles looser for warmups, but I see no advantage in the heat of play," he said.

Ritzenberg is recently back from playing a tournament in Po rtschach, a major tennis center in southern Austria. He reported that a tennis buddy, Gardnar Mulloy, was assigned a court next to one where two women were playing topless. Ritzenberg doesn't expect that style to catch on, either.