IMPROS'PEROUS, adjective [in and prosperous.] Not prosperous; not successful; unfortunate; not yielding profit; not advancing interest; as an improsperous undertaking or voyage.
[Unprosperous is the word most generally used in the sense.]
Webster's Dictionary 1828
IMPROS'PEROUS, adjective [in and prosperous.] Not prosperous; not successful; unfortunate; not yielding profit; not advancing interest; as an improsperous undertaking or voyage.
[Unprosperous is the word most generally used in the sense.]