A Montgomery County high school teacher who plagiarized the work of a student at her school was suspended for a year without pay last night by the County Board of Education.

The board's action, which came on a 5-to-2 vote, imposes a substantially stiffer penalty on Kathryn Megyeri, an 18-year veteran of the county schools, than the probation she was given earlier this year by former superintendent Edward Andrews.

The vote came during a brief special session of the school board three days after the board, meeting in executive session, informally accepted the recommendation of a hearing examiner who recommended that Megyeri, 39, be suspended, but not fired.

Megyeri, who taught English at Winston Churchill High School in Potomac, was paid $500 for an article published in the March 29 issue of Woman's World magazine that contained verbatim portions of a fictional essay written by Brenda Way. Way's story, about a teen-age abortion, was published last year in the school's literary magazine, Erehwon, and won an honorable mention in the school's fiction contest. Way and Megyeri both say they have never met.

Megyeri also published an article in February in her home-town newspaper in Minnesota that included substantial portions of a story written by Washington Post reporter Myra McPherson that appeared in the Style section of The Post last November.

In his report to the board, school officials said, the hearing examiner cited Megyeri's long tenure and good record as factors against dismissing her. But he favored a stiffer penalty than the probation recommended by Andrews because he said she had been guilty of plagiarism twice.

Megyeri gave the hearing examiner no defense or explanation for her actions, according to board members. Once the board officially approves the suspension, she will have the right to appeal to the State Board of Education.

Megyeri said yesterday that she was unaware that the board had decided to suspend her. "You're hitting me cold," she said. "I have nothing to say. I better wait and see what happens."

Although only one board member strenuously favored firing Megyeri in the closed meeting earlier this week, one member suggested that Megyeri be required to enroll in a directed study program at American University and write papers on plagiarism and ethics.

That proposal was not adopted.

Two board members reportedly felt the four-month probation was sufficient punishment and were against a one-year suspension.

Board Member Suzanne Peyser, the only member to comment publicly on the suspension last night, said the board's decision was "a terrible injustice to an excellent teacher. This punishment is overkill. I don't know how this severe punishment will improve education for children in this county." Peyser and Marian Greenblatt were the two board members who opposed the suspension.

Megyeri received a bachelor's degree in English and speech from St. Olaf College in Minnesota in 1965, and received a master's degree in English and education in 1969 from George Washington University. Last year she earned another master's degree at GWU in gerontology, the study of the aging. In her resume she lists numerous free-lance articles.

Megyeri tried unsuccessfully to be appointed to a vacant seat on the school board last year when former board member Elizabeth Spencer resigned to run for Congress. According to school system sources, Megyeri was a strong supporter of the conservative board majority that was replaced in last fall's elections.