Rehabilitation is an ungainly word. But it has been nicely defined as "what happens after the stitches are out and the fever is down, the program that trains the individual to live with what he has left."

Its message, for many, is that helplessness is not necessary.

The crushed, the wasted, the chronically weakened or ill or handicapped, the young woman whose car is suddenly smashed and her body with it, the motorcyclist whose spinal cord is abruptly severed, the arthritic or heart diseased or stroke-ridden -- almost all can be helped to go on.

But it often takes a special kind of medical facility to do the job. Chicago has the celebrated Rehabilitation Institute of Chicago; New York has the Rusk Institute; Denver, Houston, Minneapolis all have nationally recognized facilities.

Washington has not been on the list. This is true despite the fact that Arlington since 1951 has been the site of a National Orthopaedic and Rehabilitation Hospital that specializes in orthopedic surgery and treatment of arthritis and stroke. It is to a large extent a medical-surgical hospital, however, with 16 of its 147 beds allotted to rehabilitation.

Now Tuesday morning will see the formal opening and Nov. 17 the admission of the first patients to a center devoted entirely to "rehab": a new 160-bed, $41.2 million National Rehabilitation Hospital on the same grounds as the Washington Hospital Center, National Children's Medical Center and Washington Veterans Hospital. Its 160 beds will make it one of the nation's five largest such hospitals.

Calling it "national" does not make a hospital or symphony orchestra or anything else nationally noted. That takes much more. But, in the view of experts in its field, this new hospital has been assembling the kind of staff and putting together the kind of programs that could win it national regard within a decade.

The first proposal for a rehabilitation hospital came in 1981 from developer Jeffrey N. Cohen and partners. They wanted to build it at the old Children's Hospital site on 13th Street NW. The project saw three years of bureaucratic and financial ups and downs. There seemed to be little medical justification for a supposed rehabilitation hospital that stood by itself, without easy linkage with other facilities for total care.

Cohen and associates finally sold their interests to the Washington Healthcare Corp., the Washington Hospital Center's parent organization. That center's MEDSTAR shock-trauma unit would be one obvious source of patients to be rehabilitated. The D.C. government backed $41 million in tax-exempt revenue bonds to finance the project. The Healthcare Corp. scoured the country for a staff now headed by President Edward Eckenhoff from Chicago, and Dr. John Goldschmidt, medical director, from Philadelphia.

With temporary quarters in the Hospital Center, the new hospital is already a place of rehabilitation.

Dr. John Toerge from Chicago is cooperating with MEDSTAR doctors in treating the spinal cord-injured.

Dr. John Aseff from Cincinnati is aggressively treating ambulatory or "out"-patients who are already being referred to him.

Dr. Sam McFarland from San Antonio is a biomedical engineer working on new devices to help the disabled.

Dr. Gerbin de Jong from Boston is planning research in rehabilitation.

Also at work are rehab-trained nurses, social workers, physical, occupational and speech therapists, vocational counselors, psychologists, and specialists who make artificial limbs and other devices.

Will all this add to Washington area health costs? Yes, by an annual budget of perhaps $40 million in full stride. But no, Eckenhoff claims, because "more than this is being paid out already for care in acute hospitals or nursing homes," with some "very large sums" where people haven't been getting the right kind of care.

Also, he says, we will have "a different mission," not just healing the body but "returning the patient to the community" and often to a job, which returns "far more money" than the rehabilitation costs.

Not that its value can always be measured in money. Eckenhoff knows. He became a paraplegic in an auto crash as a young man, 22 years ago.

He lost the use of his legs. He moves himself around now on crutches -- and moves fast.

"But when you wake up and find your body has taken on a new image . . ." he says, and pauses.

He and his new colleagues hope to make that very hard adjustment easier.

Next Week: From HMOs to IPAs to the old Blues -- a look at all the health plans.