The phrase "milk-and-water" is used to describe something that is weak or insipid. Antonyms for this phrase could include words such as bold, strong, intense, robust, or potent. These words denote a sense of passion, strength, and vitality, which are the opposite of weak and watery. Other antonyms for "milk-and-water" could include words such as flavorful, spicy, aromatic, powerful, or pungent. These words suggest a depth and complexity that is entirely absent from something that is milk-and-water. Overall, antonyms for the phrase "milk-and-water" convey strength, richness, and flavor - qualities that are desirable in everything from food and drink to art and literature.