The phrase "break cover" typically refers to emerging from hiding, especially in a tactical or military sense. Synonyms for "break cover" might include phrases like "expose oneself," "reveal oneself," "come out of hiding," or "emerge from concealment." Alternative word choices might include "unmask," "disclose," "betray," or "unveil." In a more casual context, one might say that a person "comes out of their shell" or "steps into the spotlight" instead. The phrase "break cover" conjures images of a person or group finally revealing themselves after remaining hidden or inconspicuous, and any synonym should capture that sense of discovery or exposure.