| altitude |
in geometry, a perpendicular line segment that extends from one vertex of a figure to the opposite edge or face, or the length of such a line segment; height. [1/4 definitions] |
| birefringence |
the splitting of a light wave into two perpendicular waves that have different speeds, as in some crystals. |
| Cartesian coordinates |
a pair of coordinates for locating a point on a plane by its distances from two intersecting, usu. perpendicular lines. [2 definitions] |
| dragonfly |
any of a large group of brightly colored insects with four long, veined, translucent wings usu. held perpendicular to a long, narrow body. |
| equatorial |
a telescope mounted on two axes, one parallel to and one perpendicular to the earth's axis of rotation. [1/3 definitions] |
| equinox |
either of the two times during the year when the sun's rays are perpendicular to the earth's equator, occurring in March and September. During the equinox, day and night are both 12 hours long all over the world. |
| octant |
any of the eight parts into which three-dimensional space is divided by three mutually perpendicular planes. [1/4 definitions] |
| orthorhombic |
of or denoting a pattern of crystallization embodying three mutually perpendicular axes of different lengths. |
| perpendicular |
a perpendicular line or plane. [2/7 definitions] |
| plumb |
in a perpendicular or vertical line. [1/10 definitions] |
| precession |
the complex motion of a rotating body, such as a spinning top, when subjected to a disturbing force or torque that tends to move the axis of rotation in a direction perpendicular to the direction of the force, causing it generally to describe a cone. [1/3 definitions] |
| rake1 |
a tool consisting of a long handle and a row of tines extending perpendicular to it, used for gathering up debris or cultivating the ground. [1/12 definitions] |
| rake3 |
the angle at which a cutting or inscribing tool inclines from the perpendicular when applied to a surface. [1/4 definitions] |
| right angle |
the angle formed where two perpendicular lines meet. It measures ninety degrees. |
| square |
forming a right angle; perpendicular. [1/24 definitions] |
| up-and-down |
vertical or perpendicular. [1/3 definitions] |
| vertical |
perpendicular to level ground; extending at right angles to the horizon; upright. [1/4 definitions] |
| vertical circle |
an imaginary circle on the celestial sphere that passes through the zenith and nadir and is thus perpendicular to the horizon. |