Pronunciation: (klis'tron, klī'stron, -strun),[key]Trademark. a brand name for a vacuum tube containing an electron gun, a resonator that changes the velocity of the electron beam in accordance with a signal (buncher resonator), a drift tube in which the electron velocity does not change, another resonator that abstracts energy from the electron beam (catcher resonator), and an electrode that collects the electrons (collector electrode). It has several ultra-high-frequency applications. Cf. resonator (def. 4).