RichThesaurus
at once
vs
in two shakes (of a lamb's tail)
at once
adv
At the same time; simultaneously.
Immediately; now; right away.
in two shakes (of a lamb's tail)
How often have the words
at once
and
in two shakes (of a lamb's tail)
occurred in a corpus of books?
(source:
Google Ngram Viewer
)