The phrase "own up to" means to confess or admit to something that might be troublesome or embarrassing. There are several other words and phrases that can be used in place of "own up to." These include "come clean," "confess," "admit," "acknowledge," "declare," and "fess up." Each word or phrase has a slightly different connotation, which can make them more or less appropriate depending on the situation. For example, "confess" implies a sense of guilt, while "acknowledge" focuses more on simply recognizing and admitting to a fact. Regardless of which synonym is used, it's important to be honest and take responsibility for our actions.