From Longman Dictionary of Contemporary Englishon the edge of somethingon the edge of somethingclose to the point at which something different, especially something bad, will happen Their economy is on the edge of collapse. She is on the edge of despair. → edge
Examples from the Corpus
on the edge of something• Gripsholm Castle is built on the edge of Lake Mälar, not far from Strängnäs.• He was waiting for her answer, not exactly on the edge of his seat, though.• We're on the edge of our seats.• She found a bathroom further along, and sat on the edge of the bath.• She slid out of bed and sat on the edge of his cot.• I rested for a few minutes, then sat on the edge of the bed and looked around.• But from where we stand, they appear to be teetering on the edge of financial -- and societal -- disaster.• It is a dangerous moment, pregnant with hope teetering on the edge of despair. 