Don Adams, who died Sunday at 82, played the indefatigable, impertinent, and incompetent Maxwell Smart, code name Agent 86, in the 1960s comedy series “Get Smart.”

The role represented the apogee of Adams’s career, which essentially never recovered from it; so thoroughly was he identified with the bumbling operative that he was rarely cast as anything dissimilar. The series ran for five years, ending in 1970.

A serious-minded man with passions for military history, golf, painting, and the ponies, Adams was anything but the wise-cracking nincompoop he played on television. Savvy enough to negotiate himself an ownership stake in the heavily syndicated “Get Smart” at the outset, he lived comfortably off the residuals. He also participated in several abortive revivals of “Get Smart,” made occasional guest appearances, and did extensive voice work, including a long-running gig as the voice of Inspector Gadget.

Still, it was all a bit of a comedown for the self-professed “actor who does comedy.” Adams regularly said he craved dramatic roles. In 1969, “Get Smart” plots grew thinner and Agent 86 went so far as to marry and reproduce with Agent 99 (played by the gamine Barbara Feldon). Distressed and correctly sensing the franchise had been exhausted, he said in an interview, “I hate performing. It was never anything more to me than a means to get behind the scenes in show business.” If so, it didn’t work.

Adams, born Donald James Yarmy, was raised in New York, where his father, a Hungarian Jew, managed a series of restaurants. Although he sometimes said he wished he had studied engineering, Adams was a mediocre student at DeWitt Clinton High School, “Mr. Hooky,” as he called himself in a 1966 Saturday Evening Post interview. “I’d head for school and never make it. I’d end up on Forty-Second Street. I saw movies all the time. … I saw Rhett Butler a hundred times.” He had a talent for drawing.

In 1941, Adams dropped out of school and joined the Marines. He was in combat at Guadalcanal, but was hospitalized for a year after contracting black water fever. He later served as a drill instructor, which he once said helped him develop his distinctive nasal acting voice; his speaking voice was an octave lower.

After the war, Adams hooked up with a high school pal, and the two hitched to Miami, where they found work in beachfront comedy clubs doing impressions. The high school afternoons spent at the movies were finally paying off, Adams said. He would later credit his Maxwell Smart persona to an imitation of William Powell in “The Thin Man,” although it is difficult to find the urbane Powell in the clumsy Smart.

The clubs were awful, “the toilets of the world,” Adams said, and within a few years, he had married, had kids, and moved to Washington, D.C., where he found work as a graphic artist. On the weekends, he worked comedy clubs in Baltimore. In 1954, he teamed with comedian Bill Dana to write new material and had a breakthrough when he auditioned for Arthur Godfrey. Soon, Adams was appearing on “The Steve Allen Show,” Ed Sullivan’s “The Toast of the Town,” and got a regular job on “The Perry Como Show.” He also played in summer stock and appeared in a brief run on Broadway opposite Anthony Perkins in “Harold” in 1962.

The following year, he landed a recurring role on “The Bill Dana Show” as an inept hotel detective. It proved a worthy forerunner to Maxwell Smart, whose creators Mel Brooks and Buck Henry considered to be a sort of James Bond meets Inspector Clouseau. Although Smart was the creation of others, Adams brought to the role many of his long-tested taglines, which soon became part of the American idiom: “Would you believe …” for some outrageous confabulation, “Missed it by that much!” and “and loving it!” were all apparently his creations. One much repeated line from the show became part of NASA history when a urine bag broke aboard Gemini VII in 1966, and someone from Mission Control told astronaut Jim Lovell, “Sorry about that, chief.”

He won three Emmys during the run of “Get Smart.” Although he had vowed to quit acting when the show ended in 1970, by 1971 he was back in “The Partners,” a short-lived comedy that had him playing a bumbling police officer. He later briefly hosted “Don Adams’ Screen Test,” in which he directed stars and amateur actors in scenes from famous films.

Adams founded an advertising agency while still playing Agent 86, and in the 1970s, he produced a number of commercials and won a Clio award. He made some forays into theater and took up painting. In 1978, his third wife, Judy (there had been two divorces), told personality columnist Maggie Daly of the Chicago Tribune, “He plays golf a lot and is not as surly as people said he used to be.” The marriage did not last long.

Agent 86 was revived, much to Adams’s displeasure, in 1981’s “The Nude Bomb” and then again, more felicitously, in 1989 and 1995. Adams began exhibiting his paintings in the early 1980s and continued working on his golf game. He was frequently found at the racetrack or in card games at the Playboy Mansion with pals like Hugh Hefner, James Caan, and Don Rickles. Speaking of his voice role in the cartoon series “Inspector Gadget,” he told Entertainment Weekly, “I never saw one of them. They aired at 8 a.m. on Saturdays. I wouldn’t get up for the Second Coming at 8 a.m.”

In recent years, he had been ill with lymphoma, and his health took a turn for the worse when his daughter Cecily Adams died last year.

Don Adams

Born Donald James Yarmy on April 13, 1923; died September 25 of a lung infection at Cedars-Sinai Hospital in Beverly Hills; survived by five daughters, a son, five grandchildren, and three great-grandchildren.