All 5 Uses

prologue
in
Hamlet, Prince of Denmark
(Auto-generated)

In the most high and palmy state of Rome,
A little ere the mightiest Julius fell,
The graves stood tenantless, and the sheeted dead
Did squeak and gibber in the Roman streets;
As, stars with trains of fire and dews of blood,
Disasters in the sun; and the moist star,
Upon whose influence Neptune's empire stands,
Was sick almost to doomsday with eclipse:
And even the like precurse of fierce events,—As harbingers preceding still the fates,
And prologue to the omen coming on,—Have heaven and earth together demonstrated
Unto our climature and countrymen.†
Scene 1.1
[Enter Prologue.†
Scene 3.2
Is this a prologue, or the posy of a ring?†
Scene 3.2 *
To my sick soul, as sin's true nature is,
Each toy seems Prologue to some great amiss:
So full of artless jealousy is guilt,
It spills itself in fearing to be spilt.†
Scene 4.5
Being thus benetted round with villanies,—Or I could make a prologue to my brains,
They had begun the play,—I sat me down;
Devis'd a new commission; wrote it fair:
I once did hold it, as our statists do,
A baseness to write fair, and labour'd much
How to forget that learning; but, sir, now
It did me yeoman's service.†
Scene 5.2

Definitions:

(1) (prologue)
an introduction to a fictional work; or anything that precedes a more important event
(2) (meaning too rare to warrant focus)
Rarely, prologue can be used in other senses. For example, in Shakespeare's A Midsummer Night's Dream, Prologue is the name of a character who delivers a prologue in a play within the play.