Cat ‧ skill Moun ‧ tains, the /ˌkætskɪl ˈmaʊntənz $ -ˈmaʊntnz/ BrE AmE ( also the Catskills ) noun [P]
a group of mountains in the southeast of New York state, US, part of the Appalachian mountain range. From the 1920s to the 1950s they were a popular place for people to go on holiday, especially Jewish people, and there were many large, comfortable hotels there. Many Jewish entertainers worked there before they became famous. Today it is a popular place for people who live in New York City to visit at the weekend.