potential unit vs mV

potential unit and mV both are nouns.

Word	Noun	Adjective	Verb	Adverb
potential unit	Yes	No	No	No
mV	Yes	No	No	No

As nouns, mV is a hyponym of potential unit; that is, mV is a word with a more specific, narrower meaning than potential unit:

potential unit: a measure of the potential energy of a unit charge at a given point in a circuit relative to a reference point (ground)
mV: a unit of potential equal to one thousandth of a volt

Other hyponyms of potential unit include abvolt, millivolt, microvolt, nanovolt, picovolt, femtovolt, V, volt, kilovolt, kV.

potential unit (noun)	mV (noun)
a measure of the potential energy of a unit charge at a given point in a circuit relative to a reference point (ground)	a unit of potential equal to one thousandth of a volt