The lady's name has been lost, and that may be all to the good. But her fame among bridge players is assured.

When her right-hand opponent bid one spade at a tournament one day, she came immediately to life. "Two dliamonds," she cried.

A tournament director, who acts as a combination of referee and psychiatrist, was summoned. He asked whether the lady had clubs and diamonds for her bid. "Yes," she answered, "and a good hand, too."

Would that all cheating at bridge were so innocent, so easy to spot and the damage so easy to undo. But it isn't. Cheating at bridge, be it around the kitchen table or at a world championship tournament, is a fact of life.

It's impossible to judge how many players cheat, or how often, or to the detriment of how many, or with precisely what methods. Even a simple "code" of signals can take months to break. And even the most honest players can unconsciously transmit information to their partners via a kind of ESP.

"I've played with him so long," says one Washington-area plyer of her partner, "that I can tell just by the way he sits in the chair if he's doing something 'different.'"

Husband and wife, or lover and lover, are equally suspect.The theory, of course, is that if you spend so much non-bridge time around someone else, you will pick up deviations in demeanor at the table, however unconsciously. No male-female pair has ever own a major national title without a whispering campaign of some sort developing, sooner or later.

But bridge is not a Dodge City poker game. Ihe vast majority of players are as honest as the day is long. The trouble is with those who aren't. When their cheating blasts into the headlines, they and their dishonesty can become larger than the game itself.

Such has been the case three times in the past 12 years at world championships or playoffs.

One incident involved a British ppair allegedly using hand signals to indicate how many hearts each held. They looked caught dead to rights in photos submitted to a bridge tribunal, but no official sanctions were ever taken.

An Italian pair who were kicking and stepping on each other under the table, apparently to indicate which suit to lead, got off pretty much scotfree, too.

The third incident, early this year, involved America's most successful tournament pair over the past 10 years. They were accused of using the old rubber bridge system of "sniff" signals. Apparently a good, solid snort, as if to suppress a sneeze, meant "lead something ususual." But the exact methods are still a matter of speculation, since the evidence against the pair has not been made public.

They were confronted during a playoff to determine an American representative to the world championships, and they resigned from organized bridge forever, although they are now trying to sue their way back in.

In Washington tournament circles, a new anticheating system has been used for the past year, with mixed results.

A "recorder" - a player of immaculate reputation - serves as the gatherer of all cheating complaints at any tournament. It is his responsibility either to settle the complaints or to judge if they are serious enough to be passed on to a higher bridge "court." The recorder system is in effect at the biggest local tournament of the year, Washington Bridge Week, which began yesterday at a hotel in New Carollton.

But even recorders can't stop everything. The most recent local bridge "detective story" involved a pair, relatively new to the game, who suddenly began winning everything in sight about two years ago.

They were watched by experts and officials - at a distance, so suspicions would not be aroused. According to some of the watchers, even a nonplayer could have discerned that something was going on.

"On guy in the partnership gave signals to the other," said a local tournament director. "It worked in only one direction. It was ridiculous. You wouldn't have believed it. The guy looked like a third base coach - tweaking his ear, clearing his throat, rubbing his cheek."

Before a team match in a private home , the opposing pair rigged a few hands so they could deduce afterward what the cheaters' code was. But even that proved unsuccessful. Finally, however, the cheating pair was tried and barred from organized bridge for two years.

The easiest way to cheat at bridge is with your voice.

Try saying the words "four spades" in an even tempo, without diminishing the volume or inflecting anything. That's the legal way.

Now try it by fading out somewhere in the middle of the second word. That's the illegal way. To anyone who has played the game a few times, the second rendering means, "Partner, please don't bid any more. I want to play four spades."

Another good way to induce partner to pass at the right time is to fold up one's hand in the process of making the bid that you'd like partner to pass. If that doesn't work, sometimes a hard stare right into partner's eyes will.

The stare is an old favorite of those who cheat during the play, too.

If you lead a singleton to the first trick, and partner wins the trick, you would usually like very much to trump the second round of the suit. But often your singleton isn't as clear to partner as it is to you. Here's where the stare usually crops up - or the nervously lit cigarette, or the shifting in the chair, or the drumming of the fingers.

Then there are styles of making clear to partner the meaning of a double, of which there are at least six kinds.

In general, the more thunderous the voice, the more the cheater wants partner to pass. But once can also differentiate between doubles by accenting the first syllable or the second.

One can also double and start noting "the final contract" on a scorecard - before the bidding is over. Or one can double as one gazes at an opponent with disdain, or sympathy, allover one's face.

In any of these situations, the cheater's partner does not have to use his judgment, which is supposed to be what the game is all about. That's why these and all other forms of flagrant cheating are forbidden.

But there are gray areas, too - lots of them. Most involve hesitations during the bidding.

A 45-second pause, including lots of wincing and head fakes, followed by a pass may seem normal to some. Indeed, it may be normal or a beginner. But to experienced players, the "slow pass" suggests that the hesitater had enough "goodies" to at least consider bidding. That inference can be worth its weight in gold to the hesitater's partner later in the bidding.

The oldest form of bridge cheating is, of course, the simplest. It's called peeking at an opponent's hand.

This is a very hard one to prove, and an equally hard one to resist. It's also the easiest kind of cheating to stop. Sit up straight. Good for both your back and your game.

As for the pernicious and hard-to-decode forms of cheating, bridge is a long way from the videotape cameras and paid observers that would be necessary to detect them. Scutiny on this scale would be financially prohibitive, not to mention the cloying atmosphere it would create.

The trouble with bridge is that not every person plays an eight of hearts with the same hand, or with the same speed, or with his eyes and cigarette and glasses and scorecard in the same place.

Some would call this cheating. Some would also say it is the game's charm.