Attain vs Undefined - What's the difference?

As a verb attain

is to accomplish; to achieve.

lacking a definition or value.

(en verb)

To accomplish; to achieve.

To attain such a high level of proficiency requires hours of practice each day.

To get at the knowledge of; to ascertain.

* Fuller

not well attaining his meaning

To reach or come to, by progression or motion; to arrive at.

* Milton

Canaan he now attains .

* Bible, Psalms cxxxix. 6

Such knowledge is too wonderful for me; it is high, I can not attain unto it.

To come or arrive, by motion, growth, bodily exertion, or efforts toward a place, object, state, etc.; to reach.

* Bible, Acts xxvii. 12

if by any means they might attain to Phenice

* Sir Walter Scott

Nor nearer might the dogs attain .

* Cowper

to see your trees attain to the dignity of timber

* J. R. Green

Few boroughs had as yet attained to power such as this.

To reach in excellence or degree; to equal.

(obsolete) To overtake.

(Francis Bacon)

(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