Threshold/ˈθreʃhəʊld/ Definition 1 of 5Pro Tip 1/3Metaphorical Entry Often used metaphorically to refer to the start of a new experience or phase. She's on the threshold of a brilliant career. Pro Tip 2/3Emotional Steps Can carry emotional weight, suggesting a significant change or commitment. Crossing the threshold of marriage is a life-changing event. Pro Tip 3/3Entering New Implies entering a place or situation different from the current one. With his first step, he crossed the threshold into adulthood.