a combining form extracted from electron , used with nouns or combining forms, principally in the names of electron tubes ( ignitron; klystron; magnetron ) and of devices for accelerating subatomic particles ( cosmotron; cyclotron ); also, more generally, in the names of any kind of chamber or apparatus used in experiments ( biotron ).
[ by initial shortening of ELECTRON, with perh. accidental allusion to the Gk instrumental suffix -tron, as in árotron plough ]