say it: BAK-bray-king
backbreaking is an adjective meaning "characterized by effort to the point of exhaustion; especially physical effort". It carries one recorded sense.
characterized by effort to the point of exhaustion; especially physical effort
“worked their arduous way up the mining valley”
“a grueling campaign”
“hard labor”
“heavy work”
“heavy going”
“spent many laborious hours on the project”
“set a punishing pace”
Definitions, synonyms and semantic relations for backbreaking come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.