mo·men·tous 
/moʊˈmɛntəs/ adjective
/moʊˈmɛntəs/ adjective [more momentous; most momentous] : very important : having great or lasting importance
▪ My college graduation was a momentous day in my life. ▪ a momentous decision/event
▪ My college graduation was a momentous day in my life. ▪ a momentous decision/event
— mo·men·tous·ly adverb
▪ a momentously important decision
▪ a momentously important decision
