We don't have synonyms for spanish flu yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are spanish fly, spanish elm and spanish flag.
(n) :
(pathology) Alternative form of Spanish influenza. [(pathology) A form of influenza that spread to nearly every part of the world in a pandemic between 1918 and 1920, killing from 20 to 100 million people.]
(n) :
Alternative letter-case form of Spanish flu.
(n) :
(pathology) Alternative form of Spanish influenza. [(pathology) A form of influenza that spread to nearly every part of the world in a pandemic between 1918 and 1920, killing from 20 to 100 million people.]
(n) :
Alternative letter-case form of Spanish flu.