1.
immediately; without delay :
Come here at once!
2.
at the same time
SYN simultaneously :
Don't all speak at once!
I can't do two things at once.
1.
immediately; without delay :
Come here at once!
2.
at the same time
SYN simultaneously :
Don't all speak at once!
I can't do two things at once.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005