Anyhow, all together, after everything, and all the same are all synonyms for at the same time. Separately and consecutively are antonyms of at the same time. And here are 43 another word for at the same time.
All together, alongside each other, as a group, at once, at one and the same time, at one time, at the same instant/moment, concomitantly, concurrently, in chorus, in concert, in unison, simultaneously, together, and synchronously are all synonyms for at the same time.
After everything, all the same, anyhow, anyway, at any rate, be that as it may, but, come what may, despite that/everything, even so, for all that, having said that, howbeit, however, in any event, in spite of that/everything, just the same, nevertheless, nonetheless, notwithstanding, regardless, still and all, still, though, withal, yet, and natheless are all another word for at the same time.
At the same time synonym page has a variety of synonyms that differ in length. 2 synonyms with 3, 7, 12, 13, 14, and 15 letters and 1 synonym with 5, 18, 19, 21, 22, and 23 letters. 6 synonyms with 6 letters and 4 synonyms with 8, and 10 letters.
3 synonyms with 9 letters and 5 synonyms with 11 letters. For a total of 40 another word for at the same time.
He worked and studied at the same time.
They laughed and talked at the same time.
She cooked and cleaned at the same time.
The kids played and learned at the same time.
He watched TV and read at the same time.