The first time we heard of the neat acronym-like word NIMBY, it was voiced by J. Hamilton Lambert, the county executive of Fairfax County and the veteran of many a public hearing dominated by the NIMBY factor.

In fact, Lambert observed to one of my colleagues, the NIMBY folks are the ones who turn out in force at such hearings and are the ones who join in filing lawsuits if all else fails.

NIMBY? Not In My Back Yard. Sure, the proposed project under consideration may be desirable or even essential to the community. But, cry its neighbors, NIMBY--there must be a better place to put it.

The reasons most often cited are familiar: The project will cause traffic congestion, increase air pollution, reduce property values, change the character of a settled single-family-homes neighborhood, overload the schools. And never overestimate the zeal of those who make such claims, whether justified or not.

Of late, it seems to MetroScene, the Washington area has had more than its share of NIMBY projects. Let's go down a list of f'rinstances:

* Vepco plans a new high-tension power line across Northern Virginia, cutting close to subdivisions whose residents think it would be unsightly. The reaction: NIMBY.

Metro, desperately seeking locations for new and modern bus garages to replace its inefficient, nearly medieval facilities, proposes a location for a new one adjacent to Fort Lesley J. McNair in Southwest Washington. The reaction, chiefly from the Army: NIMBY.

* A group home or a halfway house is proposed for a residential neighborhood somewhere in Washington, whether in fashionable Cleveland Park or in a bleak area of the center city. The reaction from both: NIMBY.

* The state of Maryland, frustrated by the NIMBY factor in trying to locate a prison in a former industrial plant in East Baltimore, decided to move its site to a remote area of rural Somerset County. Somerset's reaction: NIMBY.

* The Fairfax County Housing Authority proposes to locate a public housing project adjacent to a town house development near Fairfax City, a proposal not known to town house buyers when they bought their homes. The reaction: NIMBY.

* Residents of some of Washington's most posh neighborhoods persuade the city government to outlaw the location of more foreign chanceries in their midst, citing the NIMBY factor, creating such a row that the State Department persuades Congress to step in and overrule the city.

Which brings us to the ultimate NIMBY, a dispatch the other day out of a suburb of St. Paul, Minn. Former vice president Walter Mondale recently bought a $200,000 home. His neighbors-to-be are protesting because, they claim, his impending presidential candidacy threatens to bring Secret Service restrictions, media turmoil and traffic jams to the neighborhood.