The famous American playwright Arthur Miller, who is best known for his play Death of a Salesman, made the following observation:
The essence of all drama is this: The chickens come home to roost.
In Miller's Death of a Salesman, Willy Loman and his entire family have to suffer because of the mistakes he made over all the years. He ends up committiing suicide. His two sons are failures and despise him.
In Act V of Shakespeare's play the evil deeds of Macbeth have brought an English army of ten thousand men to Dunsinane, along with his nemesis Macduff, and he has been deserted by many of his subjects. He tells himself:
I have lived long enough. My way of life
Is fall'n into the sere, the yellow leaf,
And that which should accompany old age,
As honor, love, obedience, troops of friends,
I must not look to have, but in their stead
Curses, not loud but deep, mouth-honor, breath
Which the poor heart would fain deny and dare not.
I think you could quote Miller’s definition of drama in your thesis statement and then go on to explain how the chickens have come home to roost in Macbeth. In Shakespeare’s play the murder of King Duncan takes place in the castle at Dunsinane, and in the last act the enemies Macbeth has made have come to Dunsinane for their revenge.
The analogy of the chickens coming home to roost is ironic and proverbial. It applies to all of us. Whatever misdeeds or mistakes we make in life will come back to haunt us even if it takes many years.