long haul is a noun meaning "a journey over a long distance". It carries 2 recorded senses.
a period of time sufficient for factors to work themselves out
“in the long run we will win”
“in the long run we will all be dead”
“he performed well over the long haul”
Definitions, synonyms and semantic relations for long haul come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.