excitron/ˈɛk.sɪˌtɹɒn/EtymologyFrom excite + -tron.nounA kind of mercury pool tube.“The two traction motors of Nos. BB-30003/4, one on each bogie, were supplied by eight single-anode, mercury-arc, air-cooled rectifiers of the excitron type, in which the arc is maintained continuously, […].”