From Longman Dictionary of Contemporary Englishevery (last) ounce of courage/energy/strength etcevery (last) ounce of courage/energy/strength etcALL/EVERYTHINGall the courage, energy etc that you have Every ounce of attention was focused on our common goal. → ounce
Examples from the Corpus
every (last) ounce of courage/energy/strength etc• It had taken every ounce of courage she possessed to board the aircraft after her last experience. 