The word "most loss-making" refers to a situation where a company or individual is experiencing significant financial deficits. Antonyms for this phrase could include "profitable," "successful," "booming," "flourishing," "thriving," "prosperous," "lucrative," "productive," "fruitful," and "advantageous." These words describe situations where a business or person is experiencing financial success and growth rather than loss. These antonyms can be used to describe businesses or individuals that are seeing increasing revenue, expanding markets, and achieving long-term financial stability. Overall, the use of antonyms for "most loss-making" help to create a positive and optimistic tone when discussing financial success.