peripheral vs incident

peripheral and incident both are nouns.

Word	Noun	Adjective	Verb	Adverb
peripheral	Yes	Yes	No	No
incident	Yes	Yes	No	No

peripheral (noun)	incident (noun)
electronic equipment external to the circuit board that contains the CPU of a computer	a single distinct event
	a public disturbance

peripheral (adjective)	incident (adjective)
on or near an edge or constituting an outer boundary; the outer area	(sometimes followed by `to') minor or casual or subordinate in significance or nature or occurring as a chance concomitant or consequence
related to the key issue but not of central importance	falling or striking of light rays on something