What does 功亏一篑 mean and its origin? What does 功亏一貫 mean in English and its origin?

And what does 貫 mean?
First, it's composed as 功亏一篑 where  


  篑 = container basket in construction  


..


  功亏一篑 =  Lack of a basketful to build the mount. / Lack of the final straw to break the camel's back (: