18–30 hol·i·days /ˌeɪtiːn ˈθɜːti ˌhɒlədiz $ -ˈθɜːrti ˌhɑːlədeɪz/ BrE AmE
group holidays for people between the ages of 18 and 30, especially people who are not married. For some people, this type of holiday has a bad reputation. They think that the young people who go on 18–30 holidays behave badly by drinking too much alcohol and having sex.