Prosecute vs Undefined - What's the difference?

As a verb prosecute

is (legal) to start criminal proceedings against.

lacking a definition or value.

(prosecut)

(legal) To start criminal proceedings against.

to prosecute a man for trespass, or for a riot

* Milton

To acquit themselves and prosecute their foes.

(legal) To charge, try.

To seek to obtain by legal process.

to prosecute a right or a claim in a court of law

To pursue something to the end.

to prosecute a scheme, hope, or claim

* Shakespeare

I am beloved of beauteous Hermia; / Why should not I, then, prosecute my right?

* prosecutable

(wikipedia undefined) (-)

Lacking a definition or value.

(mathematics, computing) That does not have a meaning and is thus not assigned an interpretation.

The result of division by zero is undefined .

* defined