Eleanore von Eltz Lenroot, 85, a former Washington real esate agent who became known for her tangles with the courts and the police in the 1950s, died of pneumonia Sunday in a nursing home in Waterford, Conn.

She was the widow of Irvine L. Lenroot, a retired judge of the U.S. Court of Customs and Patent Appeals, who died here in 1949.

Mrs. Lenroot, who worked for the real estate firm of Laura Harlan and Co., married Judge Lenroot in 1943. He formerly had served as a Wisconsin Republican in both the House and the Senate.

During her years in Washington, Mrs. Lenroot became something of a legend for her battles in the court system.

In 1950 a District policeman gave her a $2 ticket for overtime parking in the 1800 block of Jefferson Place NW. Rather than pay the fine, she appeared before Municipal Court Judge Thomas D. Quinn.

She denied that she had parked longer than the allowed limit, then proceeded to denounce the parking regulations for that residential block. The regulations were established, she said, because the president of the Board of District Commissioners lived there.

Judge Quinn pointed out that Mrs. Lenroot's testimony was straying from the question before the court. Her only avenue of protest, he added, was through the Board of District Commissioners.

He found her guilty and gaver her a choice of paying $2 or spending the day in jail. She paid the fine, but only after inquiring impertinently: "What kind of jails do you have?"

Four years later, Mrs. Lenroot again chose to challenge a District policeman. This time she was charged with obstructing an alley. The first reaction of the policeman who eventually charged her was to let her off with a warning.

But Mrs. Lenroot took a chance, expounded her own theory of driving and of traffic laws and two hours later left the precinct house with a ticket she promised to fight.

Luckily, she came out the winner in that one. An assistant corporation counsel said the policeman had charged her with the wrong infraction (it should have been for driving in the center of an alley, he said) and declined to prosecute. Mrs. Lenroot later said she wished the case had gone to trial.

The widow of the former Wisconsin Republican senator also conducted a personal fight against another Republican who represented Wisconsin in 1954: Sen. Joseph McCarthy.

She frequently wore a button inscribed, "Joe Must Go. Unseat McCarthy," particularly while attending the Senate Army-McCarthy hearings, but she failed to bother him.

Mrs. Lenroot was a native of New Haven, Conn. She graduated from the New York School of Social Work before coming to Washington. Since the mid-1950s, she had lived in California, New York, and Connecticut.

Survivors include a sister, Mrs. R. H. Rulison of Carmel, Calif., and a stepdaughter, Katharine F. Lenroot of Milwaukee.