What does ancient grudge break to new mutiny mean in romeo and Juliet?

In the play "Romeo and Juliet" by William Shakespeare, the phrase "ancient grudge break to new mutiny" refers to the hatred between the Montagues and Capulets, two feuding families in Verona. The phrase suggests that the long-standing feud between these families has flared up again, leading to new violent conflicts. The use of the word "break" emphasizes the sudden and unexpected nature of the new fighting, which erupts like a wave after a period of relative calm. The phrase sets the stage for the tragic events that follow as Romeo and Juliet, members of the opposing families, fall in love, leading to a series of disastrous consequences.