The two gunshots were simultaneous.
Source – merriam-webster
I encountered this word from the article “Lecture Me. Really” by Molly Worthen. The sentence of ” It keeps students’ minds in energetic and simultaneous action.” simultaneous will be the difficult word for me to understand the meaning of the sentence. When I searched this word on the dictionary, first time I knew this word mean and how to used it in the sentence, it was helpful.