At once, all together, and as a group are all synonyms for simultaneously. Sequentially and independently are antonyms of simultaneously. And here are 14 another word for simultaneously.
All together, as a group, at once, at one and the same time, at the same instant/moment, at the same time, concomitantly, concurrently, in chorus, in concert, in unison, together, and synchronously are all synonyms for simultaneously.
Simultaneously synonym page has a variety of synonyms that differ in length. 1 synonym with 6, 9, 11, 12, 19, and 22 letters and 4 synonyms with 8 letters. 2 synonyms with 13 letters. For a total of 12 another word for simultaneously.
They laughed and cried simultaneously together.
The two events occurred simultaneously last night.
She can sing and dance simultaneously.
They spoke simultaneously during the presentation.