The phrase "putting it on the line" refers to taking a risk or a gamble, putting oneself in a vulnerable position, or standing up for one's beliefs. Antonyms for this phrase might include "playing it safe," "lying low," "backing down," "avoiding confrontation," or "staying in one's comfort zone." Instead of putting it all on the line, one could try being cautious, taking a passive approach, shrinking away from challenges, or maintaining the status quo. However, it's important to recognize that taking risks and standing up for oneself can often lead to growth, success, and a sense of fulfillment.