Noun
a unit of potential equal to one thousandth of a volt
Source: WordNet;dBmV: dB(mV RMS ) – voltage relative to 1 millivolt across 75 Ω. citation Widely used in cable television networks, where the nominal strength of a single TV signal at the receiver terminals is about 0 dBmV. Source: Internet
These latter types were equivalent to separate relays; there was no logical AND function built in. Cunningham crossbar switches had precious-metal contacts capable of handling millivolt signals. Source: Internet