The antonyms for the phrase "chummed together" can be "separated," "disconnected," or "divided." When people are separated or disconnected, they are not in close proximity or association with each other. Likewise, when two people or groups are divided, they may have a disagreement or may be on opposite sides of an issue. These words denote a lack of unity or togetherness, in contrast to "chummed together," which suggests a close bond or friendship. It is important to recognize these antonyms as they help us understand the various nuances of language and the subtle differences in meaning between words.