From Longman Dictionary of Contemporary Englishmany moons agomany moons agoliteraryPAST a long time ago It all happened many moons ago. → moon
Examples from the Corpus
many moons ago• He left Derby many moons ago complaining they gagged him.• Several colour strains have bee bred since the original black and silver variety came out on the market many moons ago.• When I got my first laser printer many moons ago, my bank manager almost had a heart attack. 