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Related to much less: Much less than
much less do something
and do not even do this When our headlights flashed, the deer barely blinked, much less moved. They can hardly keep their Internet site running, much less guard against hackers.
And certainly not, as in He rarely talks about his outside activities, much less his family. The earliest record of this idiom is in John Milton's Paradise Lost (1671): "The world thou hast not seen, much less her glory."