at once
• immediately.
• "I fell asleep at once"
Similar:
immediately,
right away,
right now,
now,
straight away,
instantly,
instantaneously,
directly,
suddenly,
abruptly,
summarily,
forthwith,
promptly,
without delay/hesitation,
without further ado,
quickly,
as fast as possible,
as soon as possible,
fast,
speedily,
with all speed,
like a shot,
in/like a flash,
Opposite:
later,
in due course,
• at the same time; simultaneously.
• "computers that can do many things at once"
Similar:
at the same time,
at one and the same time,
at the same instant/moment,
(all) together,
simultaneously,
as a group,
in unison,
in concert,
in chorus,
Opposite:
singly,
in dribs and drabs,
at one time
• in or during a known but unspecified past period.
• "she was a nurse at one time"
Similar:
formerly,
previously,
once,
in the past,
at one point,
at some point,
once upon a time,
time was when,
in days/times gone by,
in times past,
in the (good) old days,
back in the day,
long ago,
in days/times of yore,
of yore,
sometime,
erst,
erstwhile,
whilom,
