The word "cross up" is usually used as a phrasal verb that means to confuse, deceive or mislead someone. There are several antonyms for the term that imply the opposite of "cross up". These include "clarify," "enlighten," "inform," "reveal," "unmask," "expose," and "disclose." To clarify means to make something clearer or more understandable. Enlightening someone means giving them knowledge or understanding. Informing people involves educating them about new information. To reveal means to bring something to light or to make it known. Exposing or unmasking someone is to reveal their true identity, hidden motives or intentions. Disclosing is the act of revealing something that was previously unknown or confidential.