The phrase "poor mouth" typically means to complain or exaggerate financial difficulties. However, some antonyms for this phrase could be "wealthy boast" or "rich praise," which would indicate someone who is bragging about their financial success. Another potential antonym could be "humble gratitude," which would describe someone who is grateful for their financial situation and does not feel the need to complain or boast about it. Additionally, "contented satisfaction" could serve as an antonym, describing someone who is happy with their financial state and does not feel the need to lament it.