The antonyms for the phrase "rallied round" are "divided," "disbanded," and "fragmented." Instead of coming together in a unified effort, these words imply the opposite, indicating a sense of disunity, lack of cohesion, and division among those involved. In situations where a group or community is faced with a challenge or crisis, failing to rally around a common cause can lead to widespread disarray, confusion, and ultimately failure. Thus, it is essential to encourage unity, foster communication, and create a shared sense of purpose to avoid becoming divided and losing ground.