placate vs calm

placate is not a noun while calm is a noun.

Word	Noun	Adjective	Verb	Adverb
placate	No	No	Yes	No
calm	Yes	Yes	Yes	No

As verbs, calm is a hypernym of placate; that is, calm is a word with a broader meaning than placate:

Other hypernyms of placate include calm down, lull, quiet, quieten, still, tranquilize, tranquillise, tranquillize.

placate (noun)	calm (noun)
	steadiness of mind under stress
	wind moving at less than 1 knot; 0 on the Beaufort scale

placate (adjective)	calm (adjective)
	(of weather) free from storm or wind
	not agitated; without losing self-possession

placate (verb)	calm (verb)
cause to be more favorably inclined; gain the good will of	cause to be calm or quiet as by administering a sedative to
	make steady
	make calm or still
	become quiet or calm, especially after a state of agitation