theatrically adverb2 •In a theatrical or dramatic manner.So it's not surprising that Terry McCabe's theatrically assured, combustibly comic staging is superior to Borealis Theatre's revival two months ago. — 2003 •In theaters, or in terms of the theater.The film premiered on 3 August before opening theatrically two days later.The story was a great success in novel form, but did not perform well theatrically. formsmore theatrically · most theatrically