parenthesis vs aside

parenthesis and aside both are nouns.

Word	Noun	Adjective	Verb	Adverb
parenthesis	Yes	No	No	No
aside	Yes	No	No	Yes

As nouns, parenthesis and aside are synonyms defined as:

Other synonyms of parenthesis include digression, divagation, excursus.

parenthesis (noun)	aside (noun)
either of two punctuation marks (or) used to enclose textual material	a line spoken by an actor to the audience but not intended for others on the stage
a message that departs from the main subject	a message that departs from the main subject

parenthesis (adverb)	aside (adverb)
	on or to one side
	out of the way (especially away from one's thoughts)
	in reserve; not for immediate use
	not taken into account or excluded from consideration
	placed or kept separate and distinct as for a purpose
	in a different direction