"Eurosclerosis" is the latest label to be pinned on the continuing and worrisome failure of Europe to catch up to Japan and the United States in economic activity and technological achievement.

"Like other illnesses with a similar name, this, of course, is often assumed to be irreversible and incurable," said Lamberto Dini, director general of the Bank of Italy. He delivered a post- election lecture at Harvard University in honor of Paul-Henri Spaak, the Belgian who helped get the European Common Market started in 1955.

According to Dini, a key actor on the international monetary scene, the symptoms of "Eurosclerosis" are high unemployment, low economic growth, and excessive labor and social-welfare costs. In addition, the hopes for economic integration of the European Community when it was founded have faded because of protectionist measures and other forms of backbiting among the nation- members of the Common Market.

Concern about Europe's future has been growing despite reassuring words from Europhiles, such as Sir Roy Denman, head of the Common Market's delegation here. He stresses Europe's postwar achievements and its enormous trade with America.

But referring to a "Europessimism" syndrome, New York Federal Reserve Bank President Tony Solomon was one of the first to observe that in Europe "there are perceptions of a waning of entrepreneurial vigor . . . and a loss of confidence among segments of both the general population and the business community."

In his provocative address, Dini said Europe's growth record and its willingness to push economic integration simultaneously ended after the 1960s. He warns that the only way for Europe to regenerate its economy is through a renewed effort to strengthen the Common Market.

"But this raises the crucial question of whether the Community is capable of taking decisions. Its recent history clearly suggests that the decision- making machinery has been paralyzed by the de facto introduction of unanimity rule in 1966," he says.

Dini's grim perspective is heightened by his belief that the health of the world economy depends on expanded forms of trilateral cooperation among the United States, Japan and Europe -- but that the real prospects for such cooperation are diminished because Europe is a weak link in the chain.

Like some others, Dini is concerned that the Pacific Basin has superseded Europe "as America's foremost trading partner." He believes that "there is a growing tendency for the U.S. media and business community to contrast the image of a sinking Europe with the rising sun of the Pacific."

Because of high interest rates and low profitability that discourages new investment, Europe has had a net loss of 1.5 million jobs in the past decade. Meanwhile, the United States, thanks to a growing service economy, added about 18 million jobs, and Japan created 5 million, according to the Paris-based Organization for Economic Cooperation and Development.

"Future prospects look much the same," according to a recent OECD report. "In Europe, the number of unemployed is forecast to rise from 18 million now (September) to nearly 20 million by the end of 1985 -- a record rate of 11.5 percent of the total European labor force."

Europe also has a distressing problem of high levels of long-term unemployment. According to the OECD, the proportion of those jobless a year or more is running around 45 percent in France, over 40 percent in England, and 30 percent in West Germany, compared with 13 percent here.

All this leads to a genuine, if reluctant, admiration for the job-creating potential of the American economy, and sets others to wondering how to duplicate it in Europe. "America has provided a powerful incentive to other countries to attack the roots of their own domestic imbalances with equal determination," Dini says.

Stephen Marris, former OECD economic adviser and now a fellow here at the Institute for International Economics, has made the point that to pick up the pace of its economic recovery, Europe needs the benefit not only of lower interest rates, but a more expansionary fiscal policy of its own. This will be possible, he believes, only when the United States really tackles its deficit.

For all of his worries, Dini insists that "Eurosclerosis" is not a permanently disabling illness. He begs the United States not to "dump" Europe as a failure. He is surely right that this would ill serve American security and political interest in a strong Atlantic Alliance.

American leaders must be concerned with how American policies affect their global partners. But by Dini's diagnosis of the sclerotic nature of Europe's disease, the real burden of the cure falls mainly on Europe itself.