"Poourish" is an uncommon word; there are few synonyms for it. Similar words that could be used in its place are "impoverished," "needy," "deprived," or "below the poverty line." These words all indicate a lack of financial resources. However, "poorish" could also refer to something that is low quality or lacking in substance. In that case, it might be substituted with "mediocre," "subpar," "shoddy," or "inferior." In general, it is best to choose synonyms that accurately convey the intended meaning of the original word.