What is breaking away/peeling off in military lingo?
I believe these are slang terms for element separation, where a leader and wingman break formation from each other either in order to reform in a new formation for tactical purposes e.g. Spread formation etc. fly a tactical maneuver to defeat a threat like a champagne or in order to land flying an overhead approach.  Wingovers are aerobatic maneuvers, very similar to Lazy Eights, intended to teach student pilots the art of flying the airplane with constantly varying stick and rudder inputs and are not involved with element separation.