The fear of youth is called ephebiphobia. First coined as the "fear or loathing of teenagers," today the phenomenon is recognized as the "inaccurate, exaggerated and sensational characterization of young people" in a range of settings around the world. Studies of the fear of youth occur in sociology and youth studies.

The word ephebiphobia is formed from the Greek ἔφηβος (éphēbos), meaning "youth" or "adolescent" and φόβος (phóbos), meaning "fear" or "phobia". The coinage of this term is attributed to a 1994 article by Kirk Astroth published in Phi Delta Kappan. Today, common usage occurs internationally by sociologists, government agencies, and youth advocacy organizations that define ephebiphobia as an abnormal or irrational and persistent fear and/or loathing of teenagers or adolescence.

The term paedophobia has gained popular acceptance in Europe to describe the aforementioned "fear of youth".Pediaphobia is the fear of infants and children. Using this term to categorize fear of youth may dismiss the unique social position that youth occupy. Hebephobia (from the Greek ἥβη, hḗbē, "youth, puberty") has also been proposed^{[citation needed]}. Similar terms include adultism, which is a predisposition towards adults that is biased against children and youth, and ageism, which describes discrimination against any person because of their age.