As long as Edward Bennet Williams owns the Baltimore Orioles, there will be speculation on when he will move the team to Washington. At his most eloquent today, the celebrated Washington lawyer assured this humble city he has no plans for a hijacking. Such eloquence you seldom hear. Even EBW's eyebrows were eloquent, rising and falling in punctuation as he said "That is my pledge to this city."

Of course, there is a catch. ". . . for so long as the city will support this team, it will stay here," Williams said.

And he reserved to himself, as the sole owner, the right to define what that support ought to be. The best definition he could give, Williams said, was that the Orioles should be supported in a style that enables the owner to put a championship team on the field.

For an owner like say Charlie Finley, a miserable million customers a year was enough to win three straight World Series; But a George Steinbrenner uses tens of millions of dollars to but his victories. "Support," then, can be anything Williams wants it to be. The only thing anyone knows for certain is that he cannot move the Orioles anywhere until the 1980 season ends, for until then the team is locked into this city by a lease of Memorial Stadium.

By the terms of that lease, incidentally, the Orioles can play as many as 13 games in Washington next season.

Williams would not commit himself on whether his team would play in Washington next season.

It will. That's an opinon. But ask yourself some questions. Did Edward Bennett Williams buy the Orioles so he could invite Ethel

Kennedy to Baltimore?Would EBW ask the noted softball pitcheer, Jimmy Carter, to throw out the first ball in Baltimore? Does Art Buchwald know where Baltimore is?

The Orioles will play at RFK next year.

But let's think big. Not any silly old 13 games. Not even bringing the WHOLE SHEBANG TO RFK.

What about a domed stadium between Washington and Baltimore?

At the press conference today, someone asked Williams about that possibility. It has been mentioned before, most often by dreamers whose dreams approach hallucination level: a $200 million domed stadium, sprouting from the roadside near Columbia, to be called the Megaplex. Home of the Capital Orioles, the Baltimore Colts and the Washington Redskins.

Asked avout a Megaplex-type stadium today, Williams beamed like a little boy who had just been given a $12 million toy and then learned that he had'nt seen the whole thing yet.

"If someone sees fit to build a magnificent new stadium between here and Washington, that would be great," Williams said, his face flushed with the prospect. Until that delightful day materializes, if it does, Williams said, "The Orioles will play in the stadium Baltimore furnishes."

The Colts' owner, Robert Irsay, has cried loud and long for a domed stadium. He surely wouldn't mind sharing a 85,000-seat place with the Redskins, who, as Williams has told us time and time again, need more than the 55,000 seats at RFK.

As for the Capital Orioles, a regional franchise could be the answer to several nettlesome baseball questions.

The old Griffith Stadium scoreboard did, Bowie Kuhn, long has promised the return of baseball to his hometown; maybe 20 miles outside the Capital Beltway would be close enough.

And while the Orioles have been wonderfully successful as artists -- American League champions in 1966, summer runaway -- mediocre attendance oorced the owner, Jerold C. Hoffberger, to be on the prowl constantly for a buyer.

A regional franchise, serving both Washington and Baltimore, could remove both those cities from baseball's list of things to worry about.

Even without our stately pleasure dome decreed, the regional franchise idea makes sense and the 13-games-in Washington clause gives Williams the perfect opportunity to test the market before, say, in 1981 he splits the entire schedule evenly between the cities.

If no new stadium materializes, then the split schedule would be discontinued -- with the baseball team going to the city that supports it best with Williams deciding the issue.

That bode ill for Baltimore because Williams is the quintessential Washingtonian -- equal parts power, prestige and puffery. He didn't put down his $12 million to be chauffeured to and fro between Potomac and Ballmer.

Jerry Hoffberger surely knows that. Attorneys for the Orioles' current owner drew up the press release announcing the sale. In the release, Williams is identified not as the quintesential Washingtonian about to spirit away the Orioles; he is "a prominent attorney who resides in Maryland."

Which is a little like saying Babe Ruth was a prominent baseball batsman who resided in the state of New York."

So we may expect the 1980 Orioles opener to be played in RFK Stadium.

It would not be the first time base ball teams have played "home" games on the road. When the Braves jillted Milwaukee in favor of Atlanta, the White Sox went to County Stadium a few times. The Brooklyn Dodgers in Walter O'Malley's days of emotional blackmail played some games in Jersey City.

And we know where the Dodgers went from Jersey City.