upend /ʌpˈɛnd/ verb4 •To end up; to set on end. •(figurative) To destroy, invalidate, overthrow, or defeat.The scientific evidence upended the popular myth. •(figurative) To affect or upset drastically.By the middle of March 2020, the COVID-19 pandemic upended normal life for virtually all Americans. •To tip or turn over.When he upended the bottle of water over his sleeping sister, the lid popped off and surprised them both. formsupended · upending · upends