Dictionary.com
Thesaurus.com

multivibrator

British  
/ ˌmʌltɪvaɪˈbreɪtə /

noun

  1. an electronic oscillator consisting of two transistors or other electronic devices, coupled so that the input of each is derived from the output of the other

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012