Lawyers for D.C. City Council Chairman Sterling Tucker asked D.C. Superior Court yesterday to dismiss a petition asking that Tucker be ousted from office for allegedly violating city restrictions on outside employment.

Responding to a removal petition filed June 6 by D.C. Corporation Counsel John R. Risher Jr., Tucker's lawyers asserted that the Council chairman's work as a lecturer at Howard University was permissible under that part of the home rule charter that limits outside employment.

Tucker's position at the school - adjunct associate professor in the school of social work - was an "honorific title," the lawyers said, with no substantial meaning.

The Council chairman's lawyers also argued that the city caused long delays in bringing action against Tucker, who for two years had voluntarily disclosed his work at Howard. In addition, they said, Tucker stopped teaching at the school a week before the court action was filed, thus mooting the question of possible improper employment.

The home rule charter requires that the Council chairman work full-time for the city and not hold any other salaried job. The chairman's salary of $35,000 is $10,000 more than that of the other 12 Council members.

Tucker became Council chairman in 1975. Until May 31, he held the position at Howard, for which he was paid more than $15,000 altogether in 1975 and 1976.

Tucker has contended that he consulted key congressmen who wrote the home rule bill and was assured that his work at the school would not be prohibited by the legislation.

He has routinely reported the income from the school in his annual financial disclosure statements submitted to the D. C. Board of Elections and Ethics.

The seven-page document filed by Tucker's lawyers yesterday does not contest the fact that Tucker worked at the school. It argues, instead, that his having a titled position was meaningless.

In both years, Tucker has said, he worked an average of about two hours a week, excluding preparation time. However, the Council chairman was unable immediately to give an exact listing of the dates on which he lectured during the 1976-77 school year.

The reference in the response filed yesterday to a delay in taking the action against Tucker seemed to underscore public statements made by Tucker that Risher's actions are politically motivated.

Tucker is frequently mentioned as a leading candidate for the Democratic mayoral nomination in 1978, and a strong potential threat to Risher's boss, Mayor Walter E. Washington, should the mayor decide to run for reelection.