What is a divorce?

This is dossolution of marriage. But I don't know why you are asking such simple questions that everyone knows or can find meaningin a dictionary. It would be better to make some discussion on the topic or write an article on this.

Divorce is the final and legal separation between a married couple by a body of law or a court...

when husband and wife or anyone start to get irritated and there is also fight. then in court they got separated called divorce

Divorce is the final and legal separation between a married couple by a body of law or a court...

Divorce is not necessarily by court. A Muslim may divorce his wife by uttering "talaque' thrice according to religious rules. Secondly, separation only means that couple are living together. Thus when court orders 'judicial separation' this is not divorce. Divorce is granted by an order called decree Nisi.

Again, the word 'divorce' is also used in context other than marriage. so when you say some thing which is idealistic or not practical, we may say: what you say is divorced from reality.

Divorce is a legal agreement for the separation of husband and wife legally and literally.