What is Long ?
Long is (adj) 1. not short in length a long piece of string The Nile is the longest river in the world. My hair needs cutting – it’s getting too long. 2. not short in time What a long programme – it lasted almost three hours. They’ve been waiting for the bus for a long time. We don’t approve of long holidays in this job. 3. indicating measurement in time How long is it before your holiday starts? long time no see! I haven’t seen you for a long time (said when meeting someone) length (adv) 1. for a long time Have you been waiting long? I didn’t want to wait any longer. Long ago, before the war, this was a wealthy farming area. all night long for the whole night It rained all night long. 2. as long as, so long as provided that I like going on picnics as long as it doesn’t rain. (noun) a long time before long in a short time She’ll be boss of the company before long. for long for a long time He wasn’t out of a job for long. the long and the short of it the basic facts The long and the short of it is that his book isn’t very good. (verb) to want something very much I’m longing for a cup of tea. Everyone was longing to be back home.
source: Easier English, Student Dictionary Upper Intermediate Level