| plane-polarized light | <chemistry> Light which is passed through a filter which blocks out all the light except that which ocillates in one plane. (09 Jan 1998) |
|---|---|
| planer | 1. One who, or that which, planes; a planing machine; especially, a machine for planing wood or metals. 2. A wooden block used for forcing down the type in a form, and making the surface even. Planer centers. See Center. Source: Websters Dictionary (01 Mar 1998) |
| planer tree | <botany> A small-leaved North American tree (Planera aquatica) related to the elm, but having a wingless, nutlike fruit. Origin: From J.S.Planer, a German botanist. Source: Websters Dictionary (01 Mar 1998) |
| planes of reference | Plane's which act as a guide to the location of other plane's. (05 Mar 2000) |
| planet | 1. <astronomy> A celestial body which revolves about the sun in an orbit of a moderate degree of eccentricity. It is distinguished from a comet by the absence of a coma, and by having a less eccentric orbit. See Solar system. The term planet was first used to distinguish those stars which have an apparent motion through the constellations from the fixed stars, which retain their relative places unchanged. The inferior planets are Mercury and Venus, which are nearer to the sun than is the earth; the superior planets are Mars, the asteroids, Jupiter, Saturn, Uranus, and Neptune, which are farther from the sun than is the earth. Primary planets are those which revolve about the sun; secondary planets, or moons, are those which revolve around the primary planets as satellites, and at the same time revolve with them about the sun. 2. A star, as influencing the fate of a men. "There's some ill planet reigns." (Shak) Planet gear. <machinery> See Epicyclic train, under Epicyclic. Planet wheel, a gear wheel which revolves around the wheel with which it meshes, in an epicyclic train. Origin: OE. Planete, F. Planete, L. Planeta, fr. Gr, and a planet; prop. Wandering, fr. To wander, fr. A wandering. Source: Websters Dictionary (01 Mar 1998) |
| planetary | 1. Of or pertaining to the planets; as, planetary inhabitants; planetary motions; planetary year. 2. Consisting of planets; as, a planetary system. 3. <astronomy> Under the dominion or influence of a planet. "Skilled in the planetary hours." 4. Caused by planets. "A planetary plague." 5. Having the nature of a planet; erratic; revolving; wandering. "Erratical and planetary life." Planetary days, the days of the week as shared among the planets known to the ancients, each having its day. Hutton. Planetary nebula, a nebula exhibiting a uniform disk, like that of a planet. Origin: Cf. L. Planetarius an astrologer, F. Planetaire planetary. See Planet. Source: Websters Dictionary (01 Mar 1998) |
| planetoid | <astronomy> A body resembling a planet; an asteroid. Origin: Planet. Source: Websters Dictionary (01 Mar 1998) |
| planets | Heavenly bodies with their own motion among the stars, revolving, in the case of the solar system, around the sun, along the plane of the ecliptic. They are grouped into inner planets and outer planets, based on distance from the sun and common characteristics. (12 Dec 1998) |
| mean foundation plane | The mean of the various irregularities in form and inclination of the basal seat; the ideal condition for denture stability exists when the mean foundation plane is most nearly at right angles to the direction of force. (05 Mar 2000) |
|---|---|
| Meckel's plane | A craniometric plane cutting the alveolar and the auricular points. (05 Mar 2000) |
| median plane | A vertical plane through the midline of the body that divides the body into right and left halves. See: Addison's clinical planes. Synonym: midsagittal plane. (05 Mar 2000) |
| pelvic plane of greatest dimensions | The plane extending from the middle of the posterior surface of the pubic symphysis to the junction of the second and third sacral vertebrae, and laterally passing through the ischial bones over the middle of the acetabulum. Synonym: second parallel pelvic plane, wide plane. (05 Mar 2000) |
| pelvic plane of inlet | The upper opening of the true pelvis, bounded anteriorly by the pubic symphysis and the pubic crest on either side, laterally by the iliopectineal lines, and posteriorly by the promontory of the sacrum. Synonym: apertura pelvis superior, aditus pelvis, first parallel pelvic plane, pelvic brim, pelvic inlet, pelvic plane of inlet, plane of inlet. (05 Mar 2000) |
| pelvic plane of least dimensions | The plane that extends from the end of the sacrum to the inferior border of the pubic symphysis; it is bounded posteriorly by the end of the sacrum, laterally by the ischial spines, and anteriorly by the inferior border of the pubic symphysis. Synonym: midplane, plane of least pelvic dimensions, plane of midpelvis, third parallel pelvic plane. (05 Mar 2000) |
| pelvic plane of outlet | The lower opening of the true pelvis, bounded anteriorly by the pubic arch, laterally by the rami of the ischium and the sacrotuberous ligament on either side, and posteriorly by these ligaments and the tip of the coccyx. Synonym: apertura pelvis inferior, apertura pelvis minoris, fourth parallel pelvic plane, pelvic outlet, pelvic plane of outlet, plane of outlet. (05 Mar 2000) |
| guide plane | A fixed or removable device used to displace a single tooth, an arch segment, or an entire arch toward an improved relationship. (05 Mar 2000) |
| midsagittal plane | A vertical plane through the midline of the body that divides the body into right and left halves. See: Addison's clinical planes. Synonym: midsagittal plane. (05 Mar 2000) |
| Morton's plane | A plane passing through the summits of the parietal and occipital protuberances. (05 Mar 2000) |
| wide plane | The plane extending from the middle of the posterior surface of the pubic symphysis to the junction of the second and third sacral vertebrae, and laterally passing through the ischial bones over the middle of the acetabulum. Synonym: second parallel pelvic plane, wide plane. (05 Mar 2000) |
| coronal plane | A vertical plane at right angles to a sagittal plane, dividing the body into anterior and posterior portions. Synonym: frontal plane. (05 Mar 2000) |
| cove plane | A classic description of terminal inversion of the electrocardiographic T wave with the initial portion arched above the baseline and the terminal portion below it, the former being rounded and the latter pointed. (05 Mar 2000) |
| popliteal plane of femur | The posterior surface of the lower end of the femur between the diverging lips of the linea aspera. Synonym: facies poplitea femoris, planum popliteum, popliteal plane of femur. (05 Mar 2000) |
| sagittal plane | <dentistry> The longitudinal vertical plane that divides the mouth into two halves (left and right.) (08 Jan 1998) |