any of the numerous minute canals lined with choanocytes which radiate from the paragastric cavity in some sponges and end just below the surface of the sponge

Either of the two plates situated on the disk at the base of each ray of some starfish. / A radial graphite reflector surrounding a pressurized water reactor.

(medicine) A surgical instrument that uses a high-frequency electric arc to cut through or cut away tissue and at the same time sterilize the edges of the wound and seal cut blood vessels.

The location of a radio transmitter by taking bearings from two receivers. / The location of a vessel or aircraft by taking bearings to two transmitters of known position.

A photophone. / A radiotelephone.

(geometry) A point at which the radical lines of three circles meet. / Pertaining to radical centrism.

A status maintained where all fixed or mobile radio stations in an area stop transmitting (sometimes limited to certain frequency bands). / The period of time during which this status exists.

(biology) The diversification of species into separate forms that each adapt to occupy a specific environmental niche.

a circular saw in which the saw wheel cuts downward from a suspended arm

(mathematics) The line containing the locus of points from which the segments respectively tangent to two given circles have equal length.