In Washington this week, the term "Art Lobby" has taken on a different -- and older -- meaning.

Believe it or not, there was a time when the lobby of the Dupont Theater had the best contemporary art shows in town. And today, despite the proliferation of commercial galleries, available exhibit space still won't satisfy demand, so lobbies all over town have been pressed into service.

In fact, you might say that these days no respectable office building, federal or otherwise, wants to be caught with its bare lobby walls exposed, and few are. The results make lunch-hour gambols to the new "art lobbies" a good idea.

"Great Ideas," the best of the current offerings, is in the lobby-gallerly of the Inter-American Development Bank, 801 17th St. NW. It includes 100 of the 200 original works of art commissioned over the past 30 years for the Container Corporation of America's much-admired "Great Ideas of Western Man" advertising campaign. It was no ordinary ad gimmick, and the scope and quality of the project will surprise even those who've been tearing out the ads and hanging them up as maxims for living.

Among those commissioned to make art interpreting the words of Jefferson, Emerson, Freud and Einstein -- to mention only a few in the series -- is no lesser light than Joseph Cornell, who made one of his magical boxes for CCA back in 1957. There are works by Cuevas and Larry Rivers (a large painted and collaged triptych), Ellen Lanyon, Jacob Lawrence and sculptor Leonard Baskin. Ben Shahn was commissioned twice, and prints by him, Carol Summers, Munakata, Frasconi and Hans Erni give some idea of how widely the net has been cast. Artists from 21 countries are represented.

Top photographers Wynn Bullock and Jerry Uelsmann were asked to amplify the ideas of great philosophers and writers. And though the project was suspended from '77 to '79, it recently began again with a piece by avant-gardist Agnes Denis featured in several current magazines. Tamayo and paper-maker Caroline Greenwald have been awarded commissions not yet completed. Artist-selection, incredibly, has all been done by CCA top management. They've done an extraordinary job.

The best part of the effort -- besides the fact that it has given 155 artists some hard cash -- is that reprints and posters of these ads can be ordered at $1 to $4 from CCA. An order blank comes in the back of a handout in the gallery. The show is closed weekends and open Monday through Friday, 10 to 5. CCA has also installed a paper environment at the Capital Children's Museum called "Amazination: Great Ideas with Paper." Both shows continue through June 30.

This piece and Luis Jiminez's giant painted Fiberglas cowboy, "Vaquero," installed on the NCFA's front steps, are both teasers for the summer sculpture show at Fondo de Sol, 2112 R St. NW. Entitled "Esculturas Escondidas," or hidden sculptures, this small exhibition features the work of 10 of the best-known Hispanic artists now working in the U.S., among them video artist Juan Downey and Donas dos Santos, who is showing sculpture, videotapes and fresh new drawings that retain the mystery of his earlier work, but with far greater refinement than ever before.

Pedro Lujan, whose spectacular carved wood "Condor" is on view in the GSA lobby, is represented here by good, if less spectacular work. Jiminez's sculptural portrait of his grandmother, and Fuente's mirror-encrusted duck wearing gilded baby shoes, are standouts.

The gallery is open Wednesday to Saturday, noon to 6:30 p.m. through the summer.

The cavernous lobby of the Hubert Humphrey Building, 200 Independence Ave. SW, offers a funny mix of everything from portraits of former heads of HEW to wood sculptures by Jackie Jerrara, James Surls and Frenchman Toni Grand, who has sliced a tree on the bias and leaned it against the wall. It is a rather provocative piece in this stone-cold environment. Ironically, one of Jon Peterson's "Bum Shelters," a red Fiberglas object like others he has placed around the country for the repose of the indigent, is also installed here. It is not clear what that says about the effectiveness of the Department of Health and Human Services, which inhabits the building.

The sculpture is the fallout from the recent International Sculpture Conference, but the main events are four shows from ethnically oriented community centers in four cities, including Washington, brought together by the Kuumba Learning Center of Capitol Hill. The stated goal -- "to showcase striking exhibits from community-based museums" -- brought a $25,000 grant from the Institute for Museum Services. It is a worthy goal, but the shows that came from Cincinnati, Buffalo and Cleveland are striking only in spite of how badly they were put together. There are no decent labels, nor signs to indicate where "Passages to American Urban Life" ends and "Polish American Artists of Buffalo" begins.

Nevertheless, communication has to start somewhere, and Eleanor Johnson, who got this pilot project under way, deserves a good deal of credit for dreaming it up. The show she organized -- "Works on Paper," by several good artists from Washington, among them Percy Martin, Carroll Sockwell, Michael Platt, Michelle Talikah Fennell, Viola Burley, Sam Gilliam, John Ryan, Terry Atkins -- makes a visit worthwhile. Though this is not really an ethnically based show, it includes some of the best talent in town. And good artists, after all, constitute their own minority. Several good photographers from Buffalo also stand out.

The shows close July 11, after which they will travel to community centers elsewhere. Future grants for traveling shows should include funds to train someone in each location to make exhibitions that can withstand such a trip.

The Plum Gallery, Kensington's finest, has just opened a small but snazzy in-town branch in the lobby of "Charlie's Georgetown," the new food and jazz bistro in Waterfront Center, 3223 K St. NW. The premiere show features works by two gallery sculptors who also paint: William Calfee and Hilda Thorpe. It is visual fare of considerably higher order than what is usually dished up in Washington restaurants.

Calfee seems to be painting better than ever, while Thorpe proves once again that her best work is in three dimensions. Plum Gallery (which also has a fine show of "Sculpture in Many Media" at its headquarters, 3762 Howard Ave., Kensington) plans an active program of changing shows at Plum Gallery 2. If the food is as good as the talent, the collaboration should be fruitful for everyone, including the customers.