It means with a single blow, by a single action having immediate effect. Although the phrase can be traced back to the fourteenth century, the allusion latterly has been to the supposed words of the later British Prime Minister Edward Heath, in the run-up to the election of 1970. The perceived promise to cut taxes 'at a stroke', though never actually spoken by Heath, came to haunt him when he became Prime Minister.

Übersetzung:

auf einen Schlag

Gegenteil(e)

The opposite of "at a stroke" is "slowly" or "gradual".

Synonym(e):

You could also say: all at once.