| Planck's constant |
the fundamental constant in quantum mechanics that expresses the ratio of the radiant energy of one quantum to the frequency of radiation. |
| plane1 |
a flat or level surface. [7 definitions] |
| plane2 |
any of various carpentry tools with an adjustable blade, used to make surfaces of wood smooth, true, grooved, or the like. [3 definitions] |
| plane geometry |
the geometry of two-dimensional or planar figures. |
| planer |
a person or thing that planes, esp. a machine that cuts or smooths wood. |
| planer tree |
a small elm tree with ovate leaves and bearing a small, nutlike fruit which grows in moist areas of the southeast United States. |
| planet |
a large, nonluminous celestial body, esp. one of the nine in the solar system, that revolves around a star and often has one or more satellites. [2 definitions] |
| planetable |
combined form of planet. |
| plane table |
a portable drawing board mounted on a tripod which is used by surveyors in the field. |
| planetarium |
an apparatus that projects a representation of the stars, planets, and the like, usu. upon a dome-shaped ceiling. [3 definitions] |
| planetary |
of, concerning, or like a planet or planets. [3 definitions] |
| planetesimal |
any of the numerous small bodies once thought to have orbited the sun and coalesced to form the planets. |
| planet-friendly |
of or pertaining to a product or process that causes minimal harm to the environment. |
| planet gear |
a gear that meshes with and describes a circular path around another gear, esp. in an epicyclic train; planet wheel. |
| planetoid |
an asteroid. |
| planet wheel |
see "planet gear." |
| plangent |
sounding deeply or loudly. [2 definitions] |
| planimeter |
a device that measures the area of a plane figure by tracing around its entire perimeter. |
| planisphere |
a maplike projection of all or part of a sphere on a plane surface. [2 definitions] |
| plank |
a length of wood similar to, but thicker than, a board. [4 definitions] |
| planking |
planks collectively. [2 definitions] |