English definition of “long”
DISTANCE › having a large distance from one end to the other: long, brown hair long legs a long dress It's a long way to travel to work.
TIME › continuing for a large amount of time: a long film/meeting Have you been waiting a long time?
HOW LONG › used when asking for or giving information about the distance or time of something: It's about three metres long. Most of the concerts are over three hours long. How long do you want the skirt? Do you know how long the film is?
BOOK › A long book or other piece of writing has a lot of pages or words: a long article/letter → See also in the long/short run