pernicious vs subtle

pernicious and subtle both are adjectives.

Word	Noun	Adjective	Verb	Adverb
pernicious	No	Yes	No	No
subtle	No	Yes	No	No

As adjectives, pernicious and subtle are synonyms defined as:

pernicious and subtle: working or spreading in a hidden and usually injurious way

Other synonyms of pernicious include insidious.

pernicious (adjective)	subtle (adjective)
working or spreading in a hidden and usually injurious way	working or spreading in a hidden and usually injurious way
exceedingly harmful	difficult to detect or grasp by the mind or analyze
	able to make fine distinctions