1.AdjectiveUsing, containing, or within parenthesis.
"You wrote "Bob (my best friend) works in finance", but I think you should rephrase that parenthetical part."
2.AdjectiveExplaining or qualifying something.
3.AdjectiveIncidental.
4.NounA word or phrase within parentheses.
5.NounA descriptor or modifier enclosed within parentheses and put, indented, in a line of dialogue to describe how it should be acted or directed onscreen.