white hope is a noun meaning "someone (or something) expected to achieve great success in a given field". It carries one recorded sense.
someone (or something) expected to achieve great success in a given field
“this company is the great white hope of the nuclear industry's waste management policy”
Definitions, synonyms and semantic relations for white hope come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.