(astronomy, celestial mechanics) An orbital parameter of a celestial body (in an elliptic orbit); the mean motion multiplied by the time since the last passage through periapsis; the angle PCM (measured in radians) defined by P = the periapsis, C = the center of the elliptical orbit, and M = the mean planet.

(astronomy, celestial mechanics) An imaginary celestial body (corresponding to another, real, orbiting one) which orbits with constant speed along an auxiliary circle (a circle which shares a diameter with the major axis of the elliptical orbit of the corresponding real celestial body), such that its position coincides with the position of the corresponding, real celestial body when that body passes through periapsis.

The average of the squares of a set of numbers.

The mean absolute deviation. / A commonly accepted standard or value.

(idiomatic) Within an urban environment, a district or set of locales in which there is a high incidence of poverty, crime, disrepair, antisocial behavior, or other adverse conditions.

(idiomatic) A defect in character characterized by persistent nastiness, viciousness, or malevolence.

simple past tense and past participle of mean-mug

present participle of mean-mug

(colloquial) A delaying filler. / (colloquial) A mild intensifier. / (colloquial) An indication of approximation or uncertainty.

(African-American Vernacular, transitive) To shoot a dirty look at (someone); to express hostility or menace towards (someone) through a dirty look.