"Opening hostilities" is a phrase used to describe the beginning of a conflict or war. Other synonyms for this phrase include "commencement of hostilities," "initiation of conflict," "start of fighting," and "launch of warfare." Additionally, terms like "first engagement," "initial confrontation," and "primary skirmish" can also be used in place of "opening hostilities." These synonyms provide a variety of alternative expressions that can add variety and flair to written or spoken discussions of tense and conflict-filled situations. Each phrase conveys a slightly different flavor or nuance, allowing writers and speakers to choose the precise terminology that best matches their intended tone and message.