matron vs married woman

matron and married woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
matron	Yes	No	No	No
married woman	Yes	No	No	No

As nouns, married woman is a hypernym of matron; that is, married woman is a word with a broader meaning than matron:

matron: a married woman (usually middle-aged with children) who is staid and dignified
married woman: a married woman; a man's partner in marriage

Other hypernyms of matron include wife.

matron (noun)	married woman (noun)
a married woman (usually middle-aged with children) who is staid and dignified	a married woman; a man's partner in marriage
a woman in charge of nursing in a medical institution
a wardress in a prison