Eccentricity

eccentricity, in astronomy: see orbit.

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eccentricity

1. deviation from a circular path or orbit

2. a measure of the noncircularity of an elliptical orbit, the distance between the foci divided by the length of the major axis

3. Geometry a number that expresses the shape of a conic section: the ratio of the distance of a point on the curve from a fixed point (the focus) to the distance of the point from a fixed line (the directrix)

4. the degree of displacement of the geometric centre of a rotating part from the true centre, esp of the axis of rotation of a wheel or shaft

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eccentricity [‚ek·sən′tris·əd·ē]

(mathematics)

The ratio of the distance of a point on a conic from the focus to the distance from the directrix.

(mechanics)

The distance of the geometric center of a revolving body from the axis of rotation.

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Eccentricity

Addams Family

weird family, presented in grotesque domesticity. [TV: Terrace, I, 29]

Boynton, Nanny

travels with set of Encyclopaedia Britannica to settle disputes. [Am. Lit.: “Percy” in Stories, 634–644]

Dick, Mr.

odd but harmless old gentleman. [Br. Lit.: David Copperfield]

Doolittle, Doctor

veterinarian who talks to animals. [Children’s Lit.: Dr. Doolittle]

Flite, Miss

“ancient” ward in Chancery. [Br. Lit.: Bleak House]

Great-Aunt Dymphna

outlandish dresser who pointedly doesn’t eat meat. [Children’s Lit.: The Growing Summer, Fisher 124–127]

Havisham, Miss

jilted bride turns into witchlike old woman. [Br. Lit.: Great Expectations]

Longstocking, Pippi

outrageous, rebellious, imaginative child. [Children’s Lit.: Pippi Longstocking]

Madeline

individualist; only girl “out of line.” [Children’s Lit.: Madeline, Fisher, 196]

Madwoman of Chaillot

delightfully pixilated old woman manages to exploit the Parisian exploiters. [Fr. Lit.: The Madwoman of Chaillot, Benét, 618]

Pickwick, Mr. (Samuel)

jolly “conformist” who understands anything but the obvious. [Br. Lit.: Pickwick Papers]

Poppins, Mary

English nanny who practises levitation, flies up chimneys, etc. [Children’s Lit.: Mary Poppins, Fisher, 218]

Salus, St. Simeon

behaved queerly to share outcasts’ contempt. [Christian Hagiog.: Attwater, 311]

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Eccentricity 

in a conic section, a number equal to the ratio of a point’s distance from the focus to its distance from a directrix. The eccentricity characterizes the shape of a conic section. For example, two conic sections that have the same eccentricity are similar. The eccentricity of an ellipse is less than unity, that of a hyperbola is greater than unity, and that of a parabola is equal to unity. For the ellipse and hyperbola, the eccentricity may be defined as the ratio of the distances between the foci to the longer or real axis.