ml vs metric capacity unit

ml and metric capacity unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
ml	Yes	No	No	No
metric capacity unit	Yes	No	No	No

As nouns, metric capacity unit is a hypernym of ml; that is, metric capacity unit is a word with a broader meaning than ml:

ml (noun)	metric capacity unit (noun)
a metric unit of volume equal to one thousandth of a liter	a capacity unit defined in metric terms