Selective vs Undefined - What's the difference?

As adjectives the difference between selective and undefined

is that selective is while undefined is lacking a definition or value.

(en adjective)

Of or pertaining to the process of selection.(rfex)

(of a person) choosy, fussy or discriminating when selecting.

He's very selective and spent hours in the store choosing a new shirt.

(chiefly, US, not comparable) Having the authority or capability to make a selection.

In the USA, military conscription is controlled by the Selective Service.

* selectiveness

(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