PM vs scrutiny

PM and scrutiny both are nouns.

Word	Noun	Adjective	Verb	Adverb
PM	Yes	No	No	No
scrutiny	Yes	No	No	No

As nouns, scrutiny is a hypernym of PM; that is, scrutiny is a word with a broader meaning than PM:

PM: an examination and dissection of a dead body to determine cause of death or the changes produced by disease
scrutiny: the act of examining something closely (as for mistakes)

Other hypernyms of PM include examination.

PM (noun)	scrutiny (noun)
an examination and dissection of a dead body to determine cause of death or the changes produced by disease	the act of examining something closely (as for mistakes)
modulation of the phase of the carrier wave	a prolonged intense look
the person who holds the position of head of the government in the United Kingdom